解析：选B。break down"坏掉，垮掉"；settle down"安顿下来"；put down"放下来"；calm down"冷静下来"。根据句意故选B。

　　2．However ________ certain natural resources may be, they cannot reproduce themselves and are bound to be used up ultimately.

　　A．rare B．abundant

　　C．valuable D．luxurious

　　解析：选B。句意：不管某些自然资源多么丰富，它们自己不会再生，终究要被用完的。abundant"丰富的"；rare"稀少的"；valuable"有价值的"；luxurious"豪华的，奢侈的"。

　　3．The growing speed of a plant is influenced by a number of factors, ________ are beyond our control.

　　A．most of them B．most of which

　　C．most of what D．most of that

　　解析：选B。本题很容易产生错误判断而选A，构成独立主格结构；然而空缺后有谓语动词are，故可否定这一选项，由句子结构可看出，后句应是most of which引导的非限制性定语从句，修饰先行词factors。

　　4．Sichuan is home _______ pandas which are fond _______ eating bamboo.

　　A．to; to B．to; of

　　C．of; to D．of; of

　　解析：选B。考查介词。句意：四川是大熊猫的栖息地，它们喜欢吃竹子。be home to"是......的家园"。be fond of"喜爱，喜欢"。

　　5．It took ________ building supplies to construct these energysaving houses.It took brains, too.

　　A．other than B．more than

　　C．rather than D．less than

　　解析：选B。句意：建造这些节能房屋不仅仅要花费建筑材料，还需要智慧。more than在句中意为"不仅仅"，修饰名词。other than"除了"；rather than"而不是"；less than"少于"。

　　6．A cricket team ________ eleven players.

A．consists of B．is consisted of