I used to be weak in English.

我以前英语很弱。

The humidification can be weak in the loss from the electric resistance.

提高湿化程度可以减小膜的欧姆损失。

I always considered myself to be weak in the English language and avoided it.

那时我总是觉得自己英语不好，所以逃避它。

The students were found to be weak in sports skills and in lack of understanding of sports.

贫困生体育行为的显著特点是对体育的认识不足，在体育技能方面偏弱。

Mr Giuliani may be weak in the early-voting states, but he leads national polls of Republican voters, albeit increasingly narrowly.

朱利安尼先生在早期投票的几个州也许不怎么样，但是他在共和党内的得票是最多的，虽然这个优势越来越小。