The old rules have to be          because they only applied to the circumstances that existed when they were made a hundred years ago.

developed

established

observed

revised

考查动词的辨析。句意：老的规则需要被修改因为它们只适合一百年制定时的状况。A.develop发展；培养；B.establish建立；C.observe观察；D.revise修改，由because they only applied to 可知它只适用于以前，需要修改。故选D项。

The most important promises we must keep are          we make to ourselves.

ones

those

these

them

考查代词。句意：我们必须遵守的最重要的承诺就是我们对自己做出的承诺。A. ones泛指上文提到的可数名词复数；B. those特指上文提到的可数名词复数；C. these这些；D.them他们。分析句子可知，为we must 是定语从句，修饰The most important promises，是句子的主语；be动词后缺少表演，we make to ourselves是定语从句，修饰空格处。根据句意，此处指上文提到的promises,由定语从句修饰表示特指，故用 those。故选B项。

I thought we'd be late for the concert,           we ended up getting there ahead of time.

but

or

so

for

考查连词。句意：我以为我们音乐会迟到了，但是我们提前到达了那里。but 但是；or 或者；so 因此；for因为；两个分句在意义上bu是转折关系，故用but。故选A项。

---Miss Yuan，you promised！

---Well，______.But it was you broke your word first.

so was I

so did I

so I was

so I did

考查强调句。句意：袁女士，你承诺过的！噢，我确实如此。但是是你先失言的。A和B是一类回答，C和D是一类回答。当别人说他自己怎么样，而你有跟他同样的情况时，用AB这样的形式回答。当别人说你怎么样，而你自己也确实是他说的那样时，用CD回答。至于用be动词还是do要根据具体语句定，谓语是be时就用be的相应形式，谓语是实意动词时就用do的相应形式。根据句意，故选D。

 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。

Going on a trip into         space must be quite         exciting experience.

/; the 

/; an

the; the 

the; an

考查冠词。句意：太空旅行是令人兴奋的经历。第一空不填，space前面不加冠词，第二空后面的experience作“经历”时是可数名词，表示“一次令人兴奋的经历"。exciting首字母的发音为元音音素，因此应填an。故选B项。

The sunlight is white and blinding,           hard-edged shadows on the ground.

throwing

being thrown

to throw

to be thrown

考查非谓语动词。句意：阳光炽白炫目，在地上投下浓重的阴影。主语The sunlight和throw是主动关系，因此要用现在分词表主动，此处是现在分词短语作状语。故选A项。

— Father, you promised!

—Well,____．But it was you who didn't keep your word first．

so was I 

so did I 

so I was 

so I did

考查部分倒装“So + be/情态动词/助动词 + 主语”与表强调的“So + 主语 + be/情态动词/助动词”区别。根据语境“you promised（你许诺过）”和答语“But it was …”可知爸爸回答“我的确许诺过”，且promised是过去时，所以表强调要用助动词did,故选D。句意：——爸爸，你许诺过。——好啦，我的确许诺过。但是是你先没有遵守诺言。

Like other animals, we are          until we know it is safe to relax.

on purpose

on fire

on guard

on duty

考查介词短语辨析。句意：像其他动物一样，我们在知道安全的时候才放松警惕。A.on purpose 故意；B. on fire着火；C.on guard 警惕；D.on duty值班。结合后文we know it is safe to relax，可知我们在知道安全的时候才放松警惕。故选C项。