句子分析： It is the period of time filled with love
我觉得，对于 it takes for a cycle to repeat itself 这部分来说，it是形式主语，to repeat itself是真正的主语，翻译的时候应该是：一个循环重复自己所需要的时间 是它的一个周期。
但愿人长久，千里共婵娟。
We wish each other a long life so as to share the beauty of this graceful moonlight, even though miles apart.
独在异乡为异客，每逢佳节倍思亲。
A lonely stranger in a strange land I am cast, I miss my family all the more on every festive day.
大江东去，浪淘尽，千古风流人物。
The endless river eastward flows; with its huge waves are gone all those gallant heroes of bygone years.
二人同心，其利断金。
If two people are of the same mind, their sharpness can cut through metal.
富贵不能淫，贫贱不能移，威武不能曲，此之谓大丈夫。
It is a true great man whom no money and rank can confuse, no poverty and hardship can shake, and no power and force can suffocate.
海内存知己，天涯若比邻。
A bosom friend afar brings distance near.
合抱之木，生于毫末，九层之台，起于累土；千里之行始于足下。
A huge tree that fills one’s arms grows from a tiny seedling; a nine-storied tower rises from a heap of earth; a thousand li journey starts with the first step.
祸兮，福之所依；福兮，祸之所伏。
Misfortune, that is where happiness depends; happiness, that is where misfortune underlies.
见贤思齐焉，见不贤而内自省也。
On seeing a man of virtue, try to become his equal; on seeing a man without virtue, examine yourself not to have the same defects.
江山如此多娇，引无数英雄尽折腰。
This land so rich in beauty has made countless heroes bow in homage.
举头望明月，低头思故乡。
Raising my head, I see the moon so bright; withdrawing my eyes, my nostalgia comes around.
俱往矣，数风流人物，还看今朝。
All are past and gone; we look to this age for truly great men.
君子成人之美，不成人之恶。
The gentleman helps others to achieve their moral perfection but not their evil conduct.
君子独立不惭于影，独寝不愧于魂。
A righteous man never feels ashamed to face his shadow when standing alone and to face his soul when sleeping alone.
君子之交淡如水，小人之交甘如醴。君子淡以亲，小人甘以绝。
The friendship between men of virtue is light like water, yet affectionate; the friendship between men without virtue is sweet like wine, yet easily broken.
老吾老以及人之老，幼吾幼以及人之幼。
Expend the respect of the aged in one’s family to that of other families; expend the love of the young ones in one’s family to that of other families.
礼尚往来。往而不来，非礼也；来而不往，亦非礼也。
Propriety suggests reciprocity. It is not propriety not to give out but to receive, or vice versa.
两情若是长久时，又岂在朝朝暮暮。
If love between both sides can last for aye, why need they stay together night and day?
路漫漫其修远兮，吾将上下而求索。
The way ahead is long; I see no ending, yet high and low I’ll search with my will unbending.
民为贵，社稷次之，君为轻。
The people are the most important element in a state; next are the gods of land and grain; least is the ruler himself.
千丈之堤，以蝼蚁之穴溃；百尺之屋，以突隙之烟焚。
A long dike will collapse because of an ant-hole in it; a tall building will be burned down by a spark from a chimney’s chink.
锲而舍之，朽木不折，锲而不舍，金石可镂。
Carve but give up half way, even a decayed piece of wood will not break; carve without stop, even metal and stone can be engraved.
人有悲欢离合，月有阴晴阳缺，此事古难全。
People have sorrow and joy; they part and meet again. The moon dims or shines; it waxes or wanes. Nothing is perfect, not even in the olden days.
人之于文学也，犹玉之于琢磨也。
Learning and culture are to a person what polished and grinding are to jade.
三人行，必有我师焉。择其善者而从之，其不善者而改之。
Among any three people walking, I will find something to learn for sure. Their good qualities are to be followed, and their shortcomings are to be avoided.
士不可以不弘毅，任重而道远。仁以为己任，不亦重乎？死而后己，不亦远乎？
An educated gentleman cannot but be resolute and broad-minded, for he has taken up a heavy responsibility and a long course. Is it not a heavy responsibility, which is to practice benevolence? Is it not a long course, which will end only with his death?
士之为人，当理不避其难，临患忘利，遗生行义，视死如归。
A moral intellectual is one who escapes no danger in face of truth, discards personal interests in front of disaster, practices righteousness at the expense of life, and looks upon death as going home.
逝者如斯夫！不舍昼夜。
The passage of time is just like the flow of water, which goes on day and night.
顺天者存，逆天者亡。
Those who follow the Heaven’s law will survive; those who go against it will perish.
天将降大任于斯人也，必先苦其心志，劳其筋骨，饿其体肤，空乏其身，行拂乱其所为，所以动心忍性，增益其所不能。
When Heaven is about to place a great responsibility on a great man, it always first frustrates his spirit and will, exhausts his muscles and bones, exposes him to starvation and poverty, harasses him by troubles and setbacks so as to stimulate his spirit, toughen his nature and enhance his abilities.
天生我才必有用。
Heaven has endowed me with talents for eventual use.
天时不如地利，地利不如人和。
Opportunities vouchsafed by Heaven are less important than terrestrial advantages, which in turn are less important than the unity among people.
天行健，君子以自强不息。
As Heaven’s movement is ever vigorous, so must a gentleman ceaselessly strive along.
温故而知新，可以为师矣。
He who by reviewing the old can gain knowledge of the new and is fit to be a teacher.
物格而后知至，知至而后意诚，意诚而后心正，心正而后身修，身修而后家齐，家齐而后治国，国治而后天下平。
Things investigated, genuine knowledge acquired; genuine knowledge acquired ,thoughts purified; thoughts purified, hearts rectified; hearts rectified, personalities cultivated; personalities cultivated, families regulated; families regulated, the states well governed; the states well governed, the whole world will be in peace and tranquil.
相见时难别亦难。
It is unbearable to meet as well as to depart.
学不可以已。青取之于蓝，而青于蓝；冰，水为之，而寒于冰。君子博学而日参省乎己，则知明而行无过矣。
There is never an end to learning. The dye extracted from the indigo is bluer than the plant; so is the ice colder than the water. By broadly learning and constantly examining himself every day, the gentleman sharpens his awareness and makes fewer mistakes.
学而不思则罔，思而不学则殆。
Learning without thinking leads to confusion; thinking without learning ends in danger.
学而不厌，诲人不倦。
Never be contented with your study; never be impatient with your teaching.
学如逆水行舟，不进则退。
Learning is like rowing upstream: not to advance is to drop back.
有朋自远方来，不亦乐乎。
It is such a delight to have friends coming from afar.
玉不琢，不成器。人不学，不知义。
As a jade without chiseling will not become a useful object, a man without learning will not know the Way.
欲穷千里目，更上一层楼。
We widen our views three hundred miles by ascending one flight of stairs. /
Exhausting my eyes to a thousand li further, I am ascending one more story of the tower.
在天愿做比翼鸟，在地愿为连理枝。
In heaven let us be two birds flying ever together, and on earth two trees with branches interlocked forever.
不登高山，不知天之厚也；不临深渊，不知地之厚也。
One can never be aware of the height of the sky or the depth of the earth, if he does not climb up a high mountain or look down into a deep abyss.
大道之行也，天下为公。
A public spirit will rule all under the sky when the great Way prevails.
大江东去，浪淘尽，千古风流人物。
The endless river eastward flows; with its huge waves are gone all those gallant heroes of bygone years.
丹青不知老将近，富贵于我如浮云。
Absorbed in painting, you know not old age is coming; indeed, to me wealth and rank are like clouds scudding.
曲则全，枉则直，洼则盈，敝则新，少则得，多则惑。
To be part is to be whole; to be bent is to be straight; to be hollow is to be filled; to be worn out is to be renewed; to have little is to have more; to have much is to be confused
首先我们看一下中文译文来帮助更好的理解句子
“正是这段我们所经历的被爱充满的时代使我们铭记一些可以指引我们去向未来的，过去发生的事，尽管未来是不可知的。”
1."which"引导的是定语从句，修饰前面的"the period of time"。
2.你要注意的是，这个句子整体是一个强调句，由"it is…that/who…"判断，是一个固定句式。所以"that"本身为句子固定成分，起到更自然的引导句子后部分的作用。
3."as"引导的是一个原因状语从句，为了使句子更加连贯，符合中文用语习惯没有刻意地将原意“所以/由此”翻译出来。
第一个"it"指代的是"the period of time"，第二个则是"the future"。在其他相似句子中，遇到无法分清指代的情况下，可以注意前面的连接词，如例句中的"as","although"。
4.答案是DEFINITELY NO。第一个句子中"which"充当的是宾语的作用，是前段"the period of time"的替代。如果替换成"when"，句意会完全改变且不成立。
第二个句子中的"that"在第二个问题中已经讲过，是强调句的固定成分。
5.“正是这段我们所经历的被爱充满的时代使我们铭记一些可以指引我们去向未来的，过去发生的事，尽管未来是不可知的。”
这是 it is ... that 结构的强调句，内嵌多重复合句。可以去掉强调框架分析如下：
〔主语〕 the period of time filled with love which we spent 一段我们度过的充满爱的时光
—— which we spent 是嵌套的定语从句，先行词是 time）
〔谓语动词〕makes 使得
〔宾语〕us 我们
〔宾补〕remember something that happened in the past as it can lead us to the future although it is unknown. 记住过去发生的事情，因为它可以引领我们走向未来，尽管它是未知的。
—— that happened in the past 是 something 的定语从句
—— as it can lead us to the future 是原因状语从句
—— although it is unknown 是让步状语从句
为您解答
which we spent that makes us remember something that happened in the past as it can lead us to the future although it is unknown.
（1）这里的“which”引导的是（ 定语）从句，修饰前面提到的（ the perriod of time）；
（2）单词“spent”后面的“that”起什么作用？ 引导强调句
（3）这里的“as”引导的是什么从句？从句中的两个“it”分别指什么？ 原因状语从句，it指the period of time filled with love，it指the future
（4）这里的“which”能否换成“when”？不能，是指代spent 的宾语。
第二个“that”能否省去或换成“which”？为什么？不能，是引导强调句
（5）请根据以上提示翻译全句。
正是我们度过的充满爱的那些时光让我们回忆起过去，因为这些时光可以把我们带向未来，尽管这个未来是未可知的。
①：be filled with侧重于动作和装的东西 example: The basketball is filled with apples by the old man. ②：be full of 侧重于状态 example: The bottle is full of water. 区别并不大，主要看你要写句字时的侧重点 full是形容词；fill是动词。 full，fill二者均与“满”有关。 full是形容词，意思是“满的”，与of组成be full of短语。 fill做动词，意思是“装满”，与with组成be filled with,表示“用……把……装满”。
