弱于

peck at───啄；少量地吃

weakest───adj.最弱的

wink at───假装没看见；使眼色

weak acid───[化学]弱酸

weak spot───弱点

weak safety───安全性差

wear out───磨损，耗尽；穿破；使精疲力竭

I know I am weak at promoting myself.───我知道，在自我推销方面自己很弱。

His sudden smile made her go weak at the knees.───他突然笑了笑，使得她两膝发软。

If the word has become weak at conveying big corporate messages, it has become even weaker at conveying small ones.───如果文字在传递大型公司信息上变得无力，那在传递小型公司时就更无力了。

Think of her sweet smile, remember she had a good, boy weak at the sky, tears flowing drop by drop.───想起女儿甜美的笑容，忆起她曾经的好，男孩儿无力的望着天空，眼泪一滴一滴流着。

and a president who is weak at home tends to be perceived as weak abroad as well.───并且一个在国内很软弱的总统在国外往往也会被认为不够强势。

The researches at home and abroad on interpersonal self, however, appear to be quite weak at present.───但目前国内外对人际自我的研究还显得十分薄弱。

Across the ages, one in five women questioned said that they were after a man who makes them weak at the knees.───不论年龄差别，都有五分之一的受访妇女说她们追求能使她们腿发软的男性。

Armed with a bow, a sword, shield and light armour, Norse arches are weak at shooting, but can stand their ground in melee.───北欧弓箭兵装备单体弓、长剑、盾牌和轻甲，远程杀伤较弱，但近身搏杀却颇为出色。

Is the pound strong or weak at the moment?

His sudden smile made her go weak at the knees.

His smile made her go weak at the knees .

He was always weak at/in languages but strong at/in science.

John is good at French but weak at history.

Her knees went weak at the sight of him.

Her school report shows that she is weak at/in arithmetic and biology.

The shock made me go all weak at the knees.

She's rather weak at maths.