[求助]几道改错题

百思不得其解,请各位高手指教:

1.A liquid that might be a poor conductor when pure is often used to make solutions that readily transmits electricity.
答案：transmits
Transmits应该改成什么？solutions是复数主语,谓语应该用单数,改成transmit

2.Harbors are protected areas of water that can be used the transfer of passengers and cargo between ships and shore.
答案：used the
Used the应该改成什么？如果改成used to 则transfer就不对了呀？改成used to 就行了,transfer是动词

3.Someone may refuse to recognize the seriousness of an emotionally threatening situation and perceive as less threatening.
答案：perceive as
Perceive as应该改成什么？改成percieve it as

4.  Rarely has a technological development had as an impact on society as the rapid grow of electronics.
答案：grow
Grow应该改成growing,可rarely has我觉得别扭，这是什么用法,为什么对呀？rarely是副词,修饰谓语,副词提前到句首,句子要不完全倒装,助动词has提前,还原的话应该是a technological development Rarely has had as an impact on society as the rapid grow of electronics

5. Of all the art-related reference and research library in North America, that of the Metropolitan Museum of a Art in New York City is among the largest and most complete.
答案：如果Library应改为复数，那reference也应该是复数呀？library为什么不对？reference 与 research 并列,都修饰 libraries