— How’s your tour around the North Lake? Is it beautiful?— It ______ be, but it is now heavily polluted.

There ______ little water in the river.

—____________you swim?   —Yes，but I’m not a good swimmer.

As we’re students, we __________ obey the school rules.

 ---That black T-shirt with Yao Ming’s picture on it ___belong to David. He admires him a lot. ---No, it _____ be his. He hates black colour.