23．It remains to be seen when/whether the newly formed committee’s policy can be put into practice.
【解析】考查有形式主语it的主语从句。从句不缺名词。句意：新制定的委员会制度什么时候实施/是否会实施还得看情况。when指“什么时候”，whether指“是否”
24．What you said at the meeting describes a bright future for the company.
【解析】考查主语从句。从句缺少宾语。句意：你在会议上的讲话为公司描述了一个光明的未来。what表示“…的话”
25．The newcomer went to the library the other day and searched for whatever/what he could find about Mark Twain.
【解析】考查宾语从句。从句中find缺少宾语。句意：新来的前两天去了图书馆，去查找了关于Mark Twain的（所有）资料。
26．It is by no means clear what the president can do to end the strike.
【解析】考查主语从句。It形式主语，从句中do缺少宾语，故用what。句意：总统会采取什么措施来结束罢工还不清楚。
27．We choose this hotel because the price for a night here is down to $20, half of what it used to charge.
【解析】考查名词性从句的引导词。＂half of _________ it used to charge＂是$20的同位语，即原来价格的一半是现在的$20；另外，of后跟名词或名词短语构成介宾短语，所以，这里是宾语从句；宾语从句中的charge后面缺少宾语，所以用what来引导宾语从句，并充当宾语从句的宾语，故用what。
28．Jerry did not regret giving the comment but felt that he could have expressed it differently.
【解析】考查宾语从句。句意完整不缺，表示确定的事，故用that句意：Jerry不后悔给出这样的评论，但他觉得可以用别的方式来表达。
29．We promise whoever attends the party a chance to have a photo taken with the movie star.
【解析】考查宾语从句。promise后接双宾语，从句 ___ attends the party为间接宾语，a chance为直接宾语。从句中缺主语，指人，故用whoever. 句意：我们承诺给参加晚会的任何人一个和那位影星合影的机会。
30．The notice came around two in the afternoon that the meeting would be postponed.
【解析】考查同位语从句。通知的内容是确定的事，故用that。句意：下午2点左右来通知了，说会议要延期。
31．Scientists study how human brains work to make computers.
【解析】考查宾语从句。从句中不缺名词。句意：科学家们研究人类大脑的工作原理来制作电脑。how表方式。
32．It suddenly occurred to him that he had left his keys in the office.
【解析】考查含形式主语it的主语从句。固定句型“it occurred to sb that…某人突然想起…”。句意：他突然想起他把钥匙忘在办公室了。
33．Eventually, I decided to follow her and what happened truly amazed me.
【解析】考查主语从句。从句缺少主语。句意：最终我决定跟踪她，后来发生的事真的让我吃惊。what表“…的事”
34．I was so impressed by how selfless she was.
【解析】考查宾语从句。how修饰selfless，表适度，构成复合引导词。句意：我真的被她的无私所感动。
35．I didn’t understand why/how this would happen and my credit card had already been charged for the reservation.
【解析】考查名词性从句的引导词。考查宾语从句。why(为什么)引导宾语从句，表示原因；how 引导宾语从句，表示方式。
36．The new boy looked at the teacher for a few seconds and all the other students wondered what the boy would do.
【解析】考查名词性从句。what引导宾语从句，且在从句中作do 的宾语，表示"什么"。
37．Cursing my misfortune, I was wondering where I was going to spend the night when I realized that the villagers who/that had gathered around me were arguing as to who should have the honor of receiving me as a guest in their house.
【解析】考查名词性从句和定语从句的引导词。第一空考查宾语从句，where表示“在哪儿”，第二空考查宾语从句，后面整个都是realized的宾语，从句中不缺少句子成分，根据意思应用that，第三空考查定语从句，先行词为人，故用who/that, 第四空仍然考查宾语从句，who在从句中充当主语，意思为“诅咒着我的不幸，我正在想到哪儿度过这一晚，突然我意识到聚在我周围的村民们正在争论谁能够谁有幸能请我到他家去做客。”
38．As natural architects, the Pueblo Indians figured out exactly how thick the adobe walls needed to be to make the cycle work on most days.
【解析】考查名词性从句的引导词。考查宾语从句。how引导宾语从句，并修饰形容词thick,表示程度。
39．He sold or exchanged some of the milk in the towns nearby for other food and made cheese and butter for the family with what was left.
【解析】考查名词性从句的引导词。考查宾语从句。what引导宾语从句，在从句中作宾语，表示“用剩下的牛奶来作奶酪和黄油”。