练习说明
句子填空 题目要求：阅读文段，从文中挑选原词补全句子，每道题目都有特定的字数要求，以黑体加粗字标示。请把答案填到每题空缺处。
Choose NO MORE THAN TWO WORDS from the passage for each answer.
第 1 题
In some states of America, decline in number of sea otters leads to the boom of
第 2 题
An impressing case is that imported _______________ successfully tackles the plant cacti in _______________.
第 3 题
Philadelphia recovered from its _______________ when the temperature dropped dramatically.
第 4 题
_______________ is economically rich in spite of its tropical climate.
第 5 题
Aid should be used to improve agriculture rather than to improve _______________.
得分：