用括号内所给单词的适当形式填空。

【1】I ______never_______(see) such a wonderful movie before.

【2】I happened_______(meet) my old friend in the street yesterday.

【3】—_______he______(be) to Beijing before? — Yes, he has.

【4】______(thank) to your help, I can find my dog.

【5】If you______(not obey) the rules, the teacher will punish you.

【6】One of the greatest______(invent) in 20th century is light.

【7】It’s______(possible) for him to solve the problem, because it’s too hard.

【8】— The______ (develop) of new products is important to our company. Do you know?

— Yeah, it is our duty to try our best to deal with it.