Her little son fell off the boat into the water due to her carelessness. The mother couldn’t help _____because she couldn’t help _____ her son out of the danger.
No student likes ________ in the teacher’s face during the class.
—I’ m sorry that I have broken your glasses. — ____________!
______ is often the case, we have worked out the production plan.
The flu is believed _____by viruses that like to reproduce in the cells inside the human nose and throat.
—How did you find the talk this morning? —______.