People have realized that they should go on _____ balanced diet and do _____ exercise every day.
| A．a; / | B．the; an | C．the; the | D．/; an |
Most animals have little connection with animals of a different kind, _______ they hunt them for food.
| A．if | B．while | C．unless | D．as |
He loved his family, but seldom _______ spend much time with them.
| A．was he able to | B．he was able to |
| C．is he able to | D．he is able to |
A study shows that walking fast in your old age is a ______ that you will live a long life.
| A．sign | B．mark | C．symbol | D．signal |
— Where _______ you put my dictionary?
— I left it on your desk when you _______ to Tom.
| A．did; spoke | B．have; were speaking |
| C．had; were speaking | D．had; spoke |
Raising children is said to be a job _______ parents receive the least formal training.
| A．in which | B．for which | C．where | D．to what |