Students are encouraged to share their learning experience__________ their classmates.
—How many teachers are there in your school?—About two _________.
— Could you look after my pet dog for me while I am away? — _______.
— What’s your plan for this weekend? — We will go for a picnic by the river _______ it rains.
—Why was he late for school yesterday?— He overslept. By the time he got to the bus stop, the bus ________ already ______.
—Heavy smog (雾霾 )in eastern and central China seems to get more and more serious.—I agree. Something to deal with it.