从每小题的A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该选项涂黑。
11. It rains very heavily in this area, which has _______ annual rainfall of 7,000 mm, _______ ideal environment for forests．
A. the; an B. an; 不填 C. an; an D. 不填; the
12.When they got there, they found the people suffering the storm were _______food and water supplies.
A. in need of B. in praise of C. in honor of D. in place of
13. – Where is Bob？I cannot find him anywhere.
– He _______have been off long. I heard him make a call just now.
A. shouldn’t B. can’t C. mustn’t D. needn’t
