[填空题]Real-time deep-sea images have never been sent to the globe before the using of communications technologies.

[填空题]Real-time deep-sea images have never been sent to the globe before the using of communications technologies.

[填空题]In China, most talented students have been sent abroad to ______ -- chiefly at the graduate level.

[简答题]The shipping documents have been sent to you by airmail, and we hope you will soon make delivery of the goods.

[单项选择]1 The Earth might have been sent into an ice age by the break-up of a supercontinent 750 million years ago, creating a global snowball.
2 The break-up probably caused an increase in rainfall and weathering of rock, say climatologists. This would have sucked greenhouse gases out of the atmosphere and caused a run-away cooling effect. The mechanism could explain how the entire planet becomes encased in a mass of ice, as many researchers think it has done in the past.
3 The theory that the Earth was once completely frozen emerged in the 1960s, when scientists realized that global freezing could happen if the polar ice sheets grew above a certain threshold size. Because bright ice reflects sunlight and heat back into space, growing ice sheets cause further cooling. This feedback loop could tip the climate system into a deep freeze.
4 The planet could eventually thaw as carbon dioxide from volcanoes poking through the ice warm it.
5 In the late 1980s, Joe Kirschv

[单项选择]（　） for your help, we never have been able to overcome the difficulties.
A. Had it not
B. lf it were not
C. Had it not been
D. If we had not been

[单项选择]（） for your help, we’d never have been able to get over the difficulties.
A. Had it not
B. If it were not
C. Had it not been
D. If we had not been

[单项选择]（　） for your help, we’d never have been able to get over the difficulties.
A. Had it not
B. If it were not
C. Had it not been
D. If we had not been

[简答题]The shipping documents have already been sent to you by airmail, and we hope you will soon make delivery of the goods.

[单项选择]______for your help, we’’ d never have been able to get over the difficulties.
A. Had it not
B. If it were not
C. Had it not been
D. If we had not been

[单项选择]______ for you help, we’’ d never have been able to get over the difficulties.
A. Had it not been
B. If it were not
C. Had it not
D. If we had not been

[单项选择] There seems never to have been a civilization without toys, but when and how they developed is unknown. They probably came about just to give children something to do. In the ancient world, as is today, most boys played with some kinds of toys and most girls with another. In societies where social roles are rigidly determined, boys pattern their play after the activities of their fathers and girls after the tasks of their mothers. This is true because boys and girls are being prepared, even in play, to step into the roles and responsibilities of the adult world. What is remarkable about the history of toys is not so much how they changed over the centuries but how much they have remained the same. The changes have been mostly in terms of craftsmanship, mechanics, and technology. It is the universality of toys with regard to their development in all parts of the world and their persistence to the present that is amazing. In Egypt, the Americas, China, Japan and among the A
A. The craftsmanship in toy-making has remained essentially unchanged.
B. Toys have remained basically the same all through the centuries.
C. The toy industry has witnessed great leaps in technology in recent years.
D. Toys are playing an increasingly important role in shaping a child’’s character.