问题 问答题 简答题

所有的大河口都会有三角洲吗?

答案

参考答案:

也有一些河流的入海口没有形成三角洲。如我国的钱塘江口就没有三角洲。这是因为钱塘江水里的泥沙含量稀少,而且河口是非常宽阔的喇叭口形的江口,涌潮的巨大冲刷力,使泥沙不能沉积下来,即使有些泥沙侥幸留下来。堆积在钱塘江口,也难以加高,只能在水面下形成一道水下沙坎,形不成露出水面的三角洲。

选择题
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WASHINGTON, Sept. 6 (Xinhua) -- U.S. President Barack Obama on Monday announced a new plan to renew and expand the nation's roads, railways and runways, in a bid (努力) to restart the sluggish economy and to help create jobs.

Obama announced the billion-dollar infrastructure(基础设施) spending program at an event in Milwaukee, Wisconsin, marking the Labor Day holiday in the United States.

The proposal calls for investments over six years, including rebuilding and modernizing 150,000 miles (241,350 kilometers) of roads, 4,000 miles (6,430 kilometers) of railways and 150 miles ( 241 kilometers) of runways.

"It sets up an Infrastructure Bank to leverage(杠杆;利用) federal dollars and focus on the smartest investment. All of this will not only create jobs now, but will make our economy run better over the long haul," Obama said.

"This is a plan that will be fully paid for and will not add to the deficit over time," said Obama.

The U.S. unemployment rate rose to 9.6 percent in August, reflecting business reluctance to hire among uncertain economic prospects, the U.S. Labor Department reported on Friday.

The president admitted that new jobs "have not been coming fast enough" in the United States.

"These years would be some of the most difficult in our history. The problems facing working families are nothing new, but they are more serious than ever. And that makes our cause more urgent than ever," he added.

小题1:What does the underlined word “sluggish” probably mean?

A.繁荣的

B.崩溃的

C.疲软的

D.行动迅速的小题2:What’s the main idea of this passage?

A.The US president launched a new program aiming at improving the nation’s infrastructure.

B.The US unemployment rate rose according to the Labor Department.

C.These years will be the most difficult in the American history.

D.More roads, railways and runways will be rebuilt and modernized.小题3:Which of the following will be changed most in length?

A.Roads.

B.Railways.

C.Runways.

D.Highways.