（）属于槽管船。 A.运水船 B.渡船 C.滚装船 D.液化气船

金鑫经销店为某工厂代销的一种建筑材料，当每吨售价为260元时，月销售量为45吨，该经销售店为提高经营利润，准备采取降价的方式进行促销．经市场调查：当每吨售价每下降10元时，月销售量就会增加7.5吨．受人力限制，每月最多只能售出75吨，综合各种因素，每售出一吨建筑材料共需支付厂家及其它费用100元，设每吨材料售价为x（元），该经销店的月利润为y（元）．（其中x为10的整数倍）

（1）求出y与x之间的函数关系式；（不要求写出x的取值范围）．

（2）该经销店要至少获得8400元月利润，则售价应定为每吨多少元？

（3）该经销店能获得9075元月利润吗？为什么？

（4）该经销店最多能获得多少元月利润？此时售价是多少元？

可引起杵状指的疾病是（）。

A.缺铁性贫血

B.亚急性感染性心内膜炎

C.类风湿关节炎

D.佝偻病

E.肢端肥大症

Can trees talk? Yes—but not in words. Scientists have reasons to believe that trees do communicate with each other. Not long ago, researchers learned some surprising things. First a willow tree(柳树) attacked in the woods by caterpillars(毛毛虫) changed the chemistry of its leaves and made them taste so terrible that the caterpillars got tired of the leaves and stopped eating them. The even more astonishing, the tree sent out a special vapor — a signal causing its neighbors to change the chemistry of their own leaves and make them less tasty.

Communication, of course, doesn’t need to be always in words. We can talk to each other by smiling, raising our shoulders and moving our hands. We know that birds and animals use a whole vocabulary of songs, sounds, and movements. Bees dance their signals, flying in certain patterns that tell other bees where to find nectar(花蜜) for honey. So why shouldn’t trees have ways of sending messages?

小题1:Why did Caterpillars stop eating the leaves of a willow tree? (No more than 15 words)

小题2:According to the passage, how do bees communicate with each other? (No more than 5 words)

小题3:What is the main idea of this passage? (No more than 5 words)

铁路桥梁基础抢修可分为（）和构筑临时性基础两大类。

碎煤机出料量明显降低的原因？