用所给单词的适当形式填空

1. Traffic in the city____(interrupt)  by a snowstorm at that time.

2. Scientists____  (assume) there is no animal life on Mars.

3. Conditions for scientific research were improved greatly,____ ( accelerate) the country's scientific

    and technological reform.

4. Like an Apollo,he comes and____(arrest) everyone's attention.

5. You can not just____(spit) wherever you like.