求教SAT語法1.The image A(of) Uncle Sam,B(in his) red and white s

題目：

求教SAT語法
1.The image A(of) Uncle Sam,B(in his) red and white striped pants and blue coat,is used at C(certain) times to D(elucidate) a feeling of pariotism in Americans.E(No error)爲什麼是D?
2.One of the doctors who were還是was returning home sang songs.
Not one of the doctors who were還是was returning home sang songs.
3.Baby lobsters are preyed on by fish and crabs because (they don't have a hard shell yet and they cat's defend themselves with fierce claws yet).改正括號內句子
A.the lobsters still lack both hard shells and fierce claws to fend off predators
B.the lobsters don't have a hard shell yet and can't defend themselves with fierce claws yet.

解答：

elucidate 是澄清的意思
Uncle Sam 這樣穿是要「表現」美國人的愛國主義,不是澄清
2我覺得是was,就他一個人唱歌,不是所以醫生一起唱歌
3A.
選項B,and的前後沒有並列,整句亂七八糟,前面在說don't have,fierce claws 明明也是don't have 的成分,卻非要用can't defend開頭.
如果改成the lobsters don't have a hard shell or fierce claws to defend themselves yet.就可以
再問： 非常感謝!!相當清楚!! 有一個問題:2. 雖然他就一個人唱歌,但所有醫生都在回家的路上啊,who were returning home?/who was returning home?.
再答： One of the doctors who were還是was returning home sang songs. Not one of the doctors who were還是was returning home sang songs 我當時沒看清楚你的問題，你問了兩種情況 我覺得第一種情況，one of the doctors who 用 was, 因爲後面整個成分都是在介定他一個人，不關其他醫生的事 如果是第二種情況Not one of the doctors who 應該用 were, 介定的是他們大家。
再問： 謝謝!!你的回答我很滿意,能否在請教兩題? 1.Although researchers have created machines that seem A(to think for themselves), none of the researchers B(has proven) the originality (of their ideas).D(No error) 2.prep.+sb.+doing 此處sb.用賓格還是物主代詞?需要分情況討論嗎？
再答： 回答之前我想請教一下，你最後會採納最佳答案？ 因爲遇到很多隻刷題，不採納的，怕了。
再問： 自然會的,難得遇到能給我滿意回答的人.我還會給你加分的^^ 我們消息聊吧,在追問要扣我分了但不加你分的