谁来给我讲讲look up这个短语的用法？

你说的很对，但是”查找”只是其中的一个意思．LOOK UP 有很多意思
向上看， she is looking up in the sky.
尊敬 his behaviour makes me look up to him
拜访
好转
我就不一一举例了．

look up
v.
向上看, 尊敬, 仰望, 查寻, 拜访, 好转

look up
(物价)上涨
(形势)好转
查阅(字典, 资料)
访问, 探访

look up and down
仔细打量(某人); 到处寻找

look upon [on]
看作, 认为是...(接as)

look up to
敬仰, 尊重

look well
看起来健康[漂亮]; (情况)显得不错

L-you!
注意!

通常用于look up to someone,意及尊敬某人敬仰某人.
比如,I'll look up to you.我要以你为榜样.
He really looks up to her. 他真的很敬仰她的为人.

1-PHRASAL
VERB
（在参考书、列表等中）查检（事实或信息）
If
you
look
up
a
fact
or
a
piece
of
information,
you
find
it
out
by
looking
in
something
such
as
a
reference
book
or
a
list.
2-PHRASAL
VERB
拜访，探访，看望（久未见面的人）
If
you
look
someone
up,
you
visit
them
after
not
having
seen
them
for
a
long
time.
3-PHRASAL
VERB
改善；好转
If
a
situation
is
looking
up,
it
is
improving.

look up，除了表示“抬头看，往上看”之外，还表示“商业、某人的前景等转好，改善”，例如：Inflation is coming down; unemployment is coming down; things are definitely looking up! 通货膨胀正在缓解，失业率也降低了，形势确实已经好转。
look sb up在口语中表示“看望或接触某人”，比如我们可以说：Do look me up the next time you're in New York. 下次你来纽约的时候一定要来找我。
而look something up则表示“查字典，查阅资料”，例如：If you want to know how a word is used, look it up in a dictionary.如果你想知道一个词是怎样用的，就去查查字典。再比如，Look up the time of the next train in the timetable. 在火车时刻表上查一下下一趟火车的时间。