谢谢！！大全上两题看不懂～～spacecraft? seldom~or? Where once民族偏见题？

19

哪位达人记得这题，我不明白什么意思，考点又在哪？

Where once the union had acquiesced to the prejudices of its English-speaking members by supporting the imposition of an alien tax on immigrant workers, after 1897 the United Mine Workers made a determined effort to enlist Italians and Slavs in its ranks.

20.

请问spacecraft是复数概念么，为何veture不用单数呢？？

It may be another fifteen years before spacecraft from Earth again venture to Mars, a planet now known to be cold, dry, and probably lifeless.

21

答案是E, 虽然我也觉得其他选项没啥好选的，

但比较中不是只用those/that指代前文么，the ones也可以？

Only seven people this century have been killed by the great white shark, the man-eater of the movies—less than those killed by bee stings.

A.     movies—less than those

B.      movies—fewer than have been

C.      movies, which is less than those

D.     movies, a number lower than the people

E.      movies, fewer than the ones

---E, the ones?

22

不明白为何B就不行呢，答案是D~~~

The city has proposed a number of water treatment and conservation projects the cost of which raises water bills high enough so that even environmentalists are beginning to raise alarms.

A.     the cost of which raises water bills high enough so that

B.      at a cost raising water bills so high that

C.      at a cost which raises water bills high enough so

D.     whose cost will raise water bills so high that

E.      whose cost will raise water bills high enough so that

23

请问seldome并不表示否定句，但为何一定用or呢？

Seldom more than 40 feet wide or 12 feet deep but running 363 miles across the rugged wilderness of upstate New York, the Erie Canal connected the Hudson River at Albany to the Great Lakes at Buffalo, providing the port of New York City with a direct water link to the heartland of the North American continent.

Seldom-or?