如图所示,把铁块放在空容器中,沿容器壁缓慢向容器中加水至虚线处.加水过程中,铁块

题型:选择题

问题:

如图所示,把铁块放在空容器中,沿容器壁缓慢向容器中加水至虚线处.加水过程中,铁块受到浮力.则在加水的全过程中,容器底对铁块的支持力F与时间t的关系图象是

[ ]

A.

B.

C.

D.

考点:浮力及阿基米德原理力的合成与应用
题型:选择题

阅读理解。

     Kitesurfing as a water sport began in the 1980s, but didn't get popular until the end of last century. It is

also known as kiteboarding, and in some European countries as flysurfing. Kitesurfing works through wind

power (动力) by using a large kite to pull a rider on the water at high speed.

     At first, kitesurfing was a difficult and dangerous sport. Now it is becoming easier and safer because of

the safer kite design. For an able and strong person, kitesurfing can be a very fun, extremely exciting sport,

just like skating on the water with a feeling of flying. It has become more and more popular.

                                               

     Compared with other water sports, kitesurfing is easier to learn. A beginner can understand how to operate

the kite with 5-10 hours of training. And anybody aged from 13 to 65 can learn. It is not expensive to get the

equipment for kitesurfing, which costs $1,000 to 82,500. Training lessons range from $200 to $500 for two

or three hours.

     With the development of its equipment progress, kitesurfing is becoming even safer. After some training,

you can enjoy its excitement and challenging feeling. With the rising popularity of kitesurfing, most major

seaside cities have kitesurfing clubs. In China, Xiamen is the only place that has the kitesurfing club, which

provides professional kitesurfing training and equipments.

1. Kitesurfing has a history of about _____ years.

A. 30

B. 50

C. 100

D. 130

2. _____ is mentioned in the passage as the power of kitesurfing.

A. Water

B. Wind

C.The sun

D. The kite

3. The underlined word "range" in the passage means "_____" in Chinese.

A. 在……范围内变动

B. 按……顺序排列

C. 向 ……方向延伸

D. 根据……归类

4. The most important reason for the popularity of kitesurfing is that _____.

A. its price is getting lower and lower

B. more and more people are enjoying its excitement

C. its equipment progress makes it easier and safer

D. all people can learn and take part in it

5. The main idea of this passage is about _____.

A. the way of operating kitesurfing

B. the progress of kitesurfing equipment

C. the history of kitesurfing in China

D. the development of kitesurfing

题型:选择题

A-V征是一种特殊类型的水平斜视其病因有以下几种说法,正确的是()

A.肌肉附着点异常

B.水平直肌学说

C.解剖学因素

D.垂直直肌学说

E.斜肌学说

题型:选择题

根据专利法律制度的规定,下列各项中,授予专利权的有______。

A.一种恢复听力的治疗仪

B.一种新药剂的配置方法

C.技术成果奖励和提成方法

D.动物品种

题型:选择题

施工现场的产品检验状态由质检员通知材料员在物料标识牌上标明,产品检验状态分为()

A.合格

B.不合格

C.待验

D.待定

题型:选择题

分型面的类型有()。

A.平面

B.斜面

C.阶梯面

D.曲面

E.垂直面

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