Some people waste a lot of food ____ others haven't enough to eat.
| A．once | B．when | C．as | D．while |
Too much work and too little rest ____ to his illness.
| A．causes | B．forms | C．leads | D．makes |
Some experts demanded that children _______ time for sleep and play.
| A．give | B．should give | C．would be given | D．be given |
This type of jewelry is ______, so you’d better buy some as soon as possible.
| A．valueless | B．worthless | C．high | D．priceless |
_____ has already been pointed out , grammar is not a set of dead rules.
| A．As | B．It | C．That | D．Which |
Father went to his doctor for _____ about his heart trouble.
| A．an advice | B．advices | C．advice | D．some advices |