He was running along the wall ____ ____ ____ (这时候他绊倒了).

He has cut his head, and his ____ (肩膀痛).

I think ____ (天要下雨了).

(用所给单词的适当形式填空) Please have a class ____ (discuss) about the problems.

(用所给单词的适当形式填空) Five minutes of laughing is as ____ (good) for you as 15 minutes in the gym.

(用所给单词的适当形式填空) Who else can I ask to help me with my maths homework or ____ (fix) my bike.

(用所给单词的适当形式填空) It's very difficult ____ (stop) smoking but you mustn't give in.

(用所给单词的适当形式填空) When we breathe in your smoke, it's like we're smoking ____ (our).

(用所给单词的适当形式填空) It's the second ____ (big) cause of death in the world.

(用所给单词的适当形式填空) I have ____ (find) out some disturbing (令人不安的) things.