According to the recent regulation, it is required that any chemical plant that_______ along the river _______ to build a recycling center for the waste.

—What _______ the number of the students in your school?—About two thousand. A number of them _______ from the countryside.

 In our school there ______ a number of books on science and the number of them ______ growing larger and larger.

Every student as well as some teachers who _________to visit the Forbidden City_________asked to be at school gate before 6:00 in the morning.

Now the number of Chinese people working in Africa _________ more than one million.