Our teacher will us the factory next week.

How many students are there on the playground? —_________.

I find _______ necessary to take some warm and dry clothes with us during the walk.

Where is the School English Speech Contest going to be held tonight?— I’m not sure. Is it in the hall _____ can hold 300 people?

Whenever I go to Beijing, ____ is quite frequent, I will go to visit the Great Wall.