解析：考查形容词。句意：美国被称为一个大熔炉，这里有来自世界各地有着各种不同文化背景的人们。diverse多种多样的；不同的,形容词修饰名词。

9.Tom was elected(elect) chairman, for he is hardworking and responsible.

解析：考查时态语态。句意：汤姆被推选成为主席，因为他很努力有责任心。be elected被选举，强调被动动作。

10.All 152 people on board were killed in the plane crash, including(include) two Americans/ two Americans included.

解析：考查非谓语动词。句意：机上152人全部在飞机坠毁中丧生，其中包括两名美国人。

Ⅱ.单句改错

1.These ideas sound nice, but by no means they solve these practical problems.

解析：句意：这些想法听起来不错，但它们不能解决实际问题。by no means绝不，放在句首，句子要部分倒装。

2.By the time he retired, Georgesaved enough money to buy a holiday home.

解析：句意：到乔治退休时，他已攒够了买度假屋的钱。By the time从句谓语用过去时，主句谓语用过去完成时。

3.The majority of people it quite hard to live on the money they earn because prices hike in basic goods.

解析：句意：大多数人觉得靠他们赚的钱来维持生活相当困难，因为基本的日常生活用品价格飞涨。the majority of.........的大多数，作主语，谓语由of后面的名词单复数决定； people人们，集合名词，复数含义。

4.In 1492 Columbus and his crew arrived in was so-called the New World by the westerners.

解析：考查宾语从句。1492年哥伦布和他的船员到达了被西方人称为所谓新大陆的地方。由具体题干可知动词arrive需要宾语从句，同时句子was so-called the New World by the westerners需要主语，结合答案充当双重结构的引导词只能是what。

5.(2016·北京卷改编）My grandfather still plays tennis now and then, though he's in his