It's really           to know that there're only seven bones in giraffes' long necks.

amazingly

amazed

amazing

amazement

考查形容词辨析。句意：知道长颈鹿的长脖子上只有7块骨头，真是令人惊讶。分析句子结构可知，is是系动词，空格处需填形容词作表语。主语是It,指物，表示“令人惊讶的”，应填amazing。故选C项。

When            to someone,I usually say, "Pleased to meet you."

introduce

introduced

introducing

am introduced

考查过去分词和省略。句意：当我被介绍给别人时，我通常会说：“很高兴认识你”。根据句子结构可知，本句是when引导的时间状语从句，原句when I am introduced to someone,这里当从句主语与主句主语一致时，并且从句的谓语动词有be这时从句的主语与be同时省略，所以空格处introduced。故选B项。

Let's learn to use the problem we are facing         a stepping-stone to future success.

to

for

as

by

考查介词词义辨析。句意：让我们学会把我们所面对的问题作为通向未来成功的手段来利用。A.to朝，对 ；B.for 为了，对于；C.as 作为；D.by通过，凭借。根据句意可知，此处“作为”符合语境。故选C项。

It’s his brother ______ never been to Australia. You’d better take him with you.

that is

who is

that have 　

 who has

句意：就是他的弟弟从没去过澳大利亚。你最好带他和你去。根据句意及题干分析此题是考查强调句型，因为强调的是his brother，是人，所以用who引导是现在完成时态，故选D。

It was not until 1920 ___ regular radio broadcasts began.

when

which

that

since

此题考查强调句。句意为：直到1920年，常规的电台才开始。这句话把it is/was和that去掉后，仍是完整的一句话，因此我们可以知道这是一个强调句，而且是对not...until“直到...才”的强调。结构是：it is/was+not until+其他成分。故选:C.

 Is _______ three hours _______ the poor boy to come to school on foot?

it; that it takes

there; that it takes

there; when

it; that

考查强调句。强调句的结构为It’s + 强调部分 + that从句。本题强调时间状语three hours。句意：可怜的男孩步行到学校花了3个小时吗？故A正确。

It was fortunate that Jack narrowly escaped             in a traffic accident last month.

killing

being killed

to be killed

 to kill

考查非谓语动词。句意：杰克上个月在交通事故中死里逃生，真是幸运。固定表达escape doing sth.逃离做某事。此处Jack与kill之间是被动关系，应该使用动名词的被动语态，用being killed。故选B项。