The chemistry teacher warns us ________ in the laboratory.

He would have gone to visit Linda yesterday, however , he _____on by Linda instead

I want to ________a teacher when I grow up． ，amD．/

It’s unbelievable that such a small girl ____ have so much knowledge about computer.

he world economy growing weaker, for many youngpeople, the dream of landing a good job is becoming harder and harder ________.