You need to take your job________if you want to keep it.

He looked at those jewels one after another ______and seemed to show no interest in any one of them.

Professor Lee failed many times but he ________found a good way to solve the problem.

I spent most of my money in the first week and________ had very little to eat by the end of the holiday. 

 When you feel you are happier and more relaxed after having a cigarette, you may become ________addicted.