问题补充：
Apart from the shortage of water and food, the survivors in Haiti are the terrible plague(瘟疫).
A. in search of
B. in charge of
C. at the mercy of
D. as a result of
答案：
A. in search of
B. in charge of
(答案→)C. at the mercy of
D. as a result of
解析：四个选项分别表示搜寻、负责、受……支配和作为……结果，根据题意选C，除缺少食物和水之外，海地的生存者还受制于可怕地瘟疫。
