Computers are of great        to the development of science and technology.

.He is a new comer in the team, but I have the______ that I have seen that man before.

In my opinion, you can widen the _____ of these improvements through your active participation. 

The tomato juice left a brown_____ on the front of my jacket.

You were working too hard. You’d better keep a ________between work and relaxation.