There is growing tendency among middle-school students___________they will do some voluntary work during their vacation.
| A．which | B．why | C．how | D．that |
Mary had taken _____ to see that her guests had everything that they could possibly want.
| A．efforts | B．pains | C．attempts | D．endeavors |
Expected noises are usually more _____ than unexpected ones of the like magnitude.
| A．manageable | B．controllable |
| C．tolerable | D．perceivable |
Experts say walking is one of the best ways for a person to _____ healthy.
| A．preserve | B．stay | C．maintain | D．reserve |
Jack almost fell off the cliff, but managed to _____ until help came.
| A．keep on | B．catch on | C．count on | D．hang on |
The storm sweeping over this area now is sure to cause _____ of vegetables in the coming days.
| A．rarity | B．scarcity | C．invalidity | D．variety |