My grandpa is a science teacher and he _______ science.
– It’s difficult for the village children to cross the river to get to school. – We think a bridge ________ over the river.
– You seem to know much about the city. – That’s true. I _______ it four times in the last three years.
If I am free, I’d like to spend _________ holiday in the countryside.
Mrs. Wang always asks us to ________ conversations in the English classes.
Would you please drive more ________, David? The train is leaving soon.