Only when he returned ________ that the war had ended and the army had come back.

we tell

we told

did we tell

were we told

考查倒装句型。Only放在句首时，句子要用倒装语序；根据句意“我们被告知”可知，此处要用were we told。故答案选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.

The information tells me that the way of education in Canada is quite different from          in China.

one

it

that 

those

考察代词。句意：这条信息告诉我们在加拿大的教育方式和在中国的教育方式很不一样。前后比较的是教育方式，用that 指代the+名词。A. one 是泛指一个，B.it 指的是同一个东西，D. those指代the +名词复数。故选C项。

The law           equal rights for men and women.

permits

confirms

persevers

guarantees

考查动词辨析。句意：这个法律确保了男女权利平等。A.permit允许；B.confirm证实，证明；C.persever坚持；D.guarantee保证，担保。分析句意可知，空格处为动词做谓语，其主语为the law,为单数则谓语动词用第三人称单数形式。又因the law作用是保证公平。故选D项。

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。

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。