Look at the boy running on the ground. Is it Davis?—It ______ be him. I saw him go to the teacher’s office just now.

Everyone is here. Let’s ________ our class now.

Look! The farmers are still working _____ the heavy rain.[ ]

This is the first time I ______, so I feel very curious about everything here.

When did Hong Kong return to our motherland? — ____ 1997. [ ]