请教3题～

m8888302

做新东方书上的题时碰到的，也不确定答案一定正确。。

because an oversupply of computer chips has sent prices plunging , the manufacturer has announced that it will cut production by closing its factories for two days a month.

A. because an oversupply of computer chips has sent prices plunging

B. because of plunging prices for computer chips, which is due to an oversupply

C. because computer chip prices have been sent plunging, which resulted from an oversupply

D. due to plunging computer chip prices from an oversupply

E. due to an oversupply, with the result that computer chip prices have been sent plunging

答案c。根据because较好选出A,C，但之后怎么确定是C？

sceientists have dated sharp-edged flakes of stone found in the fine-grained sediments of a dry riverbed in the a far region of Ethiopia to between 2.52 and 2.60 million years ago, pushing back by more than 150000 years the earliest date when it is known that humans made stone tool.

A. when it is known that humans made

B. at which it is known that humans had made

C. at which humans are known to have made

D. that humans are known to be making

E. of humans who were known to make

答案是e.  d首先排除，b,c 时态也不太对排除，但之后又怎么选呢

the environmental protection agency's proposal to place restrictions on both diesel fuel and diesel engines has sparked a counterattack by the oil industry, saying that the move will exacerbate the nation's fuel supply problems.

A. on both diesel fuel and diesel engines has aparked a counterattack by the oil industry, saying

B. on both diesel fuel and engines have sparked the oil industry to counterattack, and they say

C. on both diesel fuel and diesel engines has sparked a counterattack by the oil industry, which says

D. both on diesel fuel and engines has sparked the oil industry to a counterattack, saying

E. both on diesel fuel and diesel engines have sparked the oil industry to counterattack, and it says

答案c。根据both..and..以及主谓一致排除b,d,e，但为何选c？

m8888302

date不是应该后面加时间定语从句么？when 或者介词+which

m8888302

第二题：因为是the earliest date ，所以D的that是不是该先排除？

这书是新东方的蓝皮教材前面的题。。。不过答案老是有错悲剧，看来不能做那个了