11. A significant proportions of the plants and animals of Hawaii exists nowhere
a b c
else in the world.
d
答案： A
解析： 注意到句首的“a”,所以這里用單數形式，改為：proportion.
12. You will not be able to pass your examination except you study harder than you
a b c
do now.
d
答案： B
解析： 表達“除非”的意思；except 改為unless。
13. Some bosses dislike to allow people to share their responsibilities; they keep
a b
all important matters tightly in their own hands.
c d
答案： A
解析： dislike doing sth. 指“不喜歡做…”。
14. Generally speaking, the bird flying across our path is observed, and the one
a b
staying on the tree near at hand is passed by without noticed.
c d
答案： D
解析： without是介詞，后面應該接名詞或動名詞，同時，該句又是被動的含義所以應改為: without being noticed.
15. On the whole, ambitious students are much likely to succeed in their studies
a b
than those with little ambition.
c d
答案： B
解析： 此句是一個包含了比較級的句子，所以B項應改為： are more likely.
