1:Although they plant trees in this area every year, the tops of some hills are still___.
A:blank B:hollow C:vacant C:bare
blank和bare都有空白的意思,该选哪个呢?
选C.
blank和bare都有空白的意思,但是bare还有裸露的意思.没有植树的山丘当然是裸露的.
2:There's an opinion___ on the facts.
A:based B:basing C:that base D:which base
选A.
这是动词过去分词做后置定语,因为是被动,所以用过去分词；如果是主动就要用现在分词basing了.
3:Over one thousand people visited the exhibition___ those who were present at the opening ceremony on the first day.
A:except B:except for C:with the exception of D:in addition to
选C.
从意思来看：超过一千人参观了展览,还不算第一天出席开幕典礼的人.
这题考察学生对于句意的理解和推测.
4:Although he had looked through all the reference materials on the subject, he still found it hard to understand this point and her explanation only___ to his confusion.
A:extended B:amounted C:added D:turned
选C.
add to是把什么增加到什么上.
尽管他查阅了关于这门学科的大量参考资料,但是他仍然觉得很难理解这一点,而且她（可能是他的老师）的解释让他更加疑惑不解.