Great amounts of water            poured into the river from the factories two years ago.

was

were

has been

have been

考查时态和主谓一致。句意：两年前，工厂将大量废水排入河中。根据two years ago 可知，句子使用一般过去时。....amounts of修饰不可数名词作主语时，谓语动词用复数形式，即谓语动词与amounts保持数的一致。故选B项。

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。

         Jixi today is more beautiful now. Mr.Jakson said he would visit it         third time.

The; /

The; the

/; a

The; a

考查冠词。句意：今天的鸡西市更漂亮了。Jakson先生说他将又一次来到这里。第一空“鸡西市”应用定冠词；第二空“不定冠词a/an+序数词+名词” 强调在已知数量上在累加一个，且 third为辅音音素开头的单词，应用a。故选D项。

My little sister          me into buying this book.

wanted

advised

persuaded

told

考查动词词义辨析。句意：我的小妹妹说服我买了这本书。A. want想，想要；B.advised 建议；C. persuaded说服，劝服；D.told告诉。want  sb to do sth想要某人做某事；advise sb to do sth 建议某人做某事；persuade sb into doing sth 劝服某人做某事；tell sb to do sth告诉某人做某事。故选C项。

Don’t mention that at the beginning of the story, or it may             the  shocking end.

give out

give away

give up

give off

考查动词短语辨析。句意：不要在故事的开头提到它，否则会泄露令人震惊的结局。A. give out分发；B. give away泄露；C.give up 放弃；D. give off发出（光），根据“the shocking end”可知，此处表示“泄露”。故选B项。

When it comes to modern communication, network safety is always a major          . 

concern

advantage

opportunity

solution

考查名词辨析。句意：当涉及现代通信，网络安全一直是一个主要令人担忧的问题。A. concern关心，令人担忧的事实或情况；B. advantage 优势；C. opportunity 机会；D.solution解决方案。网络安全一直是现代通信的个主要令人担忧的问题。故选A项。