Koalas are pictured everywhere in Austra

题型:阅读理解

问题:

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

考点:健康环保类阅读
题型:阅读理解

下列各项中,减按2元/平方米征收耕地占用税的是()。

A.纳税人临时占用耕地

B.学校占用耕地建设校舍

C.农村居民占用耕地新建住宅

D.公路线路占用耕地

题型:阅读理解

集装箱标准按使用范围分类,可分为国际标准、国家标准、地区标准和城市标准四种。

题型:阅读理解

一个函数为void f(int,charch='a'),另一个函数为void f(int),则它们

A.不能在同一程序中定义

B.可以在同一程序中定义并可重载

C.可以在同一程序中定义,但不可以重载

D.以上说法均不正确

题型:阅读理解

无水MgBr2可用作催化剂。实验室采用镁屑与液溴为原料制备无水MgBr2,装置如图1,主要步骤如下:

步骤1:三颈瓶中装入10g镁屑和150mL无水乙醚;装置B中加入15mL液溴。

步骤2:缓慢通入干燥的氮气,直至溴完全导入三颈瓶中。

步骤3:反应完毕后恢复至室温,过滤,滤液转移至另一干燥的烧瓶中,冷却至0℃,析出晶体,再过滤得三乙醚合溴化镁粗品。

步骤4:常温下用苯溶解粗品,冷却至0℃,析出晶体,过滤,洗涤得三乙醚合溴化镁,加热至160℃分解得无水MgBr2产品。

已知:①Mg和Br2反应剧烈放热;MgBr2具有强吸水性。

②MgBr2+3C2H5OC2H5≒MgBr2·3C2H5OC2H5

请回答:

(1)仪器A的名称是()。

实验中不能用干燥空气代替干燥N2,原因是()。

(2)如将装置B改为装置C(图2),可能会导致的后果是()。

(3)步骤3中,第一次过滤除去的物质是()。

(4)有关步骤4的说法,正确的是()。

A.可用95%的乙醇代替苯溶解粗品

B.洗涤晶体可选用0℃的苯

C.加热至160℃的主要目的是除去苯

D.该步骤的目的是除去乙醇和可能残留的溴

(5)为测定产品的纯度,可用EDTA(简写为Y4-)标准溶液滴定,反应的离子方程式:

Mg2++Y4-═MgY2-

①滴定前润洗滴定管的操作方法是()。

②测定前,先称取0.2500g无水MgBr2产品,溶解后,用0.0500mol·L-1的EDTA标准溶液滴定至终点,消耗EDTA标准溶液26.50mL,则测得无水MgBr2产品的纯度是()(以质量分数表示)。

题型:阅读理解

公允价值,是指按照市场价格确定的价值。( )

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