1.
To come, exist, or occur before in time.
先于…先于…之前出现、存在或发生
2.
I believe that theories are prior to observations as well as to experiments.
我认为理论先于观察，也先于实验。
3.
be before(sth/sb)in time
先于,早于（某事物[某人]）
4.
His death antedated his brother's.
他去世先于他的兄弟。
5.
The Bitter must come before the sweet; and that also make the sweet the sweeter.
苦应先于甜,会使甜更甜。
6.
that is, before any other help arrives.
也就是说，先于他人之前。
7.
beat sb to...arrive at(a place)before sb
先于某人到达（某处）
8.
The we should always precede the I.
集体总应先于个人。
9.
He dissatisfied that I am promoted precede him.
他不满我先于他被提升。
10.
He is holding a safe lead.
他稳稳地领先于其他人
11.
To appropriate, seize, or take for oneself before others.
预先占有先于他人而占用、占有或据为已有
12.
Of, relating to, or constituting a precedent.
先例性的属于、关于或组成先例的
13.
Having or granted by the right of preemption.
有先买（占）权的或被授于先买（占）权的
14.
Of,relating to,or characteristic of preemption.
先买(占)的先买(占)的、关于先买(占)的或以先买(占)为特点的
15.
Happiness lies, first of all, in health .
幸福首先在于健康。
16.
so Mr. Grey decided,
于是格雷先生决心，
17.
reposition back to its normal site, as of a broken bone, in surgery.
重新放于原先的位置。
18.
The ship will victual before sailing.
船于航行前先装贮食物。