All of us should _______our teachers as well as our parents.
Mum told Andrew ______ quiet in the museum.
My uncle is a writer. He ______ many books since he was young.
—I wonder _______. —By searching the Internet.
In China it is a custom to give kids lucky money, _______ during the Spring Festival.
People along the river didn’t allow them to ______ a factory so as not to pollute the water.