该图表示地球上的三圈环流。据图判断下列有关说法正确的是 A．

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问题选择题

该图表示地球上的三圈环流。据图判断下列有关说法正确的是

A．②为极地东风带,④为中纬信风带

B．①⑤以上升气流为主,降水较多;③⑥以下沉气流为主,降水较少

C．④在北半球为西北风,在南半球为西南风

D．①位于两极地区

答案

答案：B

①是赤道附近的上升气流，形成赤道低气压，降水多；②是信风带；③是副热带高压，形成下沉气流，降水少；④是盛行西风，北半球是西南风，南半球是西北风；⑥是极地高压，形成下沉气流，降水少。选择B项。

填空题

根据上下文或括号里的汉语提示，在下面短文的空白处写出正确的单词或词组，使短文意思完整，

语句连贯。

About more than a hundred years ago, an American produced a game. He called it 1. (室内的)

tennis. The Americans were not interested in it 2. (起初), but he sent it to his London friends and

it became very 3. (流行的) in Britain. The game was then played across dining-room tables,

or 4. (在地板上) with the net strung (用绳缚) 5. (在……之间) two chairs. The

balls 6. (由…制成) cork(软木)or rubber. The bats were made of wood. 7. (几年之后) a

hollow (空心的) ball like the one we use today was invented. The game then 8. (快速地) spread

all over the world. An Englishman once made a bat covered with rubber. He first sold the game in England

and called it "Ping-pong". "Ping" was the 9. (声音) of the bat when it hit the ball, and "pang" was

the 10. (第二) sound of the ball when it hit the table.

单项选择题

二尖瓣血流频谱哪项不对（）

A.系收缩期正向血流频谱

B.呈双峰型

C.正常时E峰流速大于A峰

D.呈空心层流

E.在老年人中可表现为A峰>E峰