用所给动词的适当形式完成句子。The teacher told us that the earth (travel) around the sun.
Students in Yancheng didn’t go to school last Thursday because of the (pollute) air.
We are not sure if humans (move) to the Mars in the future.
By the time she left college, she_________（fall）in love with the young man.
More than one student_________(progress) a lot in English since they became Grade 9 students.