6．growth　考查词性转换。此处表示控制急剧增长的人口，应用名词作宾语，故填growth。

　　7．to　考查介词。limit ... to ... "限定......到......"是固定搭配。

　　8．who/that　考查定语从句的引导词。夫妇双方均为独生子女的，还可以再生一个孩子。本处先行词为parents，关系词在定语从句中作主语，故填who/that。

　　9．a　考查冠词。序数词前用不定冠词，意为"再，又"。这里指"再生一个小孩，或可生第二个孩子"。

　　10．further　考查副词的比较级。根据句意"一孩政策进一步放松"可知，本处应用比较级；由于本处不是表距离，而是表事情的程度，故填further。

　　Ⅳ.短文改错

　　One day, an old man was returning home after shopping. Suddenly, a bag of waste fell in the sky, nearly hitting him on his head. He was greatly frightening by the unexpected incident. Dropped the things he had bought to the ground, he ran away rapidly. What dangerous it was!

　　Obviously, the accident caused by a careless neighbour living highly in an apartment. It was that person who was to blame for. Every one of us should behave politely and think more about other. Only when we each behaved properly can our society be changed into a pleasant one.

　　答案：

One day, an old man was returning home after shopping. Suddenly, a bag of waste fell the sky, nearly hitting him on head. He was greatly by the unexpected incident. the things he had bought to the ground, he ran away rapidly. dangerous it was!