You'd better go and ask him. He ____ know how to use computer.

You'd better go and ask him. He __must__ know how to use computer.
他肯定知道。

You'd better go and ask him. He __may__ know how to use computer.
他可能知道。

might may should must
都可以。语气渐强、

零分啊！不告诉你答案

shoud多给点儿分吧