问题 选择题

据2012年央视3.15晚会报道:液化石油气掺入二甲醚(C2H6O)成行业潜规则,二甲醚对液化气罐的配件有腐蚀性,严重会造成爆炸.下列关于二甲醚的说法错误的是(  )

A.由C、H、O三种元素组成

B.相对分子质量46

C.是一种氧化物

D.碳、氢、氧三种元素的质量比为12:3:8

答案

答案:C

单项选择题
阅读理解

Koalas are pictured everywhere in Australia-on cleaning products, on “boxes of chocolate, on sports team shirts. Yet the animals live only in pockets along the east coast.

They once inhabited the entire coastline. The koala population dropped after farmers cut down many of the forests where koalas lived, and hunters killed the animals for their fur.

By the early 1900s, “koalas were basically shot out of south Australia,” says ecologist Bill Ellis, who studies the relationships among living things and their environments.

I recently joined Ellis and his team in a forest on St Bees Is land, 19 miles off the northeastern coast of Australia, with eight other volunteers. The island is a natural laboratory, yielding findings that may help protect koalas elsewhere on the continent.

The volunteers searched the island for koalas in the blue gum trees. When we found a koala, we gathered information about the trees in the area.

Blue gum is a species of the eucalyptus tree in which the funny leaf eaters spend most of their time. Eucalyptus trees are native to Australia, and their leaves are the main food source for koalas. Although koalas can walk on the ground, they are better suited for life in the canopy, the high cover of branches and leaves in a forest.

What has Ellis’s research told him so far? The population of St Bees seems to be healthy. Yet Ellis wonders whether the koalas might be heading for hard times. The island is overrun with wild goats, and Ellis thinks the goats are eating the small blue gum trees.

Without those trees, the koalas will run out of food in the future. Ellis hopes more research will help him understand how to protect the blue gum trees-and the koalas that depend on them. “I think that’s what everyone is trying to do-to make a difference.” Ellis says.

59. It can be inferred from the first paragraph that     .

A. koalas’ pictures can be found everywhere in the world

B. koalas in Australia like to eat chocolate

C. only in the east coast of Australia can you find koalas

D. you can buy the pictures of koalas only in the east coast of Australia

60. Which of the following is TRUE about koalas?

A. They usually hide in a cave.     B. They feed on the leaves of blue gum trees.

C. They prefer to walk on the ground.  D. They don’t adapt to the high cover of branches.

61. What will Ellis most probably start to do next?

A. To keep the population of St Bees healthy.

B. To kill all the goats on the island.

C. To find some new foods for goats.

D. To protect blue gum trees for koalas.

62. The purpose of writing this passage is to      .

A. expect people to concern about the life of koalas

B. record trip to Australia for watching koalas

C. present some basic knowledge of koalas’ life

D. introduce the ecosystem of wildlife in Australia