I'll never forget the most wonderful holiday ________(我们住在乡下的)with my grandparents．(stay)

He chose one large stone and began to hit one of the scrapers hard on the edge ________(需要磨锋利的)．(sharpen)

With the rapid development of medical science, we ________(会看到)more new drugs used in the treatment of cancer．(see)

Under a new ten－year plan, our company ________(正在改变)into an international corporation．(transform)

They soon realized that, unless carefully ________(处理), the situation would become even worse．(deal)

Not until the teacher explained it again ________(我们才理解)the sentence．(sense)

________(无论他多么晚), his mother would wait for him to have dinner together．(however)

He ________(仍拿不定主意)over whether to join the expedition．(hesitate)

I didn't know his telephone number otherwise I ________(会给他打电话)．(telephone)

I explained to her that last night it was already eleven p.m．________(飞机起飞), so I didn't ring to disturb her．(take)