[求助]这两道题怎么做啊？

1.        Although it claims to delve into political issues, television can be superficial such as when each of the three major networks broadcast exactly the same statement from a political candidate.

(A) superficial such as when each of the three major networks

(B) superficial, as can sometimes occur if all of the three major networks

(C) superficial if the three major networks all

(D) superficial whenever each of the three major networks

(E) superficial, as when the three major networks each

2.        Although some officials noted that using machines for farming in China costs more than traditional hand cultivation, the mechanization of farming in the village of Long Bow doubled the corn yield while the previous year’s costs were cut in half.

(A) mechanization of farming in the village of Long Bow doubled the corn yield while the previous year’s costs were cut in half

(B) mechanization of farming in the village of Long Bow doubled the corn yield while cutting costs to half those of the previous year

(C) mechanization of farming in the village of Long Bow doubled the corn yield as cost were cut to half of the previous year’s

(D) farming mechanization in the village of Long Bow doubled the corn yield as it cut in half the previous year’s costs

(E) farming mechanization in the village of Long Bow doubled the corn yield while costs were cut to half that of the previous year

为什么要选这两个答案阿？

第一题，each of the three跟单数，排除AD。If引导条件状语从句表示事件还未发生，不符合题意，排除BC。总之记住if不可随意添加。

第二题，while表示伴随和强对比关系，不能随意替换，排除CD。A说去年的成本减半，逻辑意思不正确。E的that不能指代前面的costs，排除。另外C的cost were错，D的it指代也不明确。

谢谢！

谢谢！