---The book is borrowed from the library. You ____ your children touch it with their dirty hands.　---Sorry.　   

The impatient driver received a ticket for speeding. He       so fast.

The Chinese teacher looks so pale. She ___ be ill.

Swimming alone ___be ____dangerous. Do be careful.

The results of the medical checkup suggested that my father ______ in poor health, so the doctor suggested that he ______ smoking and take more exercise.