绕弯儿可能引起的中毒食物是（）。 A.玉米、小麦、大米 B.肉类 C.蛋类 D.鱼类

中度牙弓拥挤为（）

A.2～4mm

B.3～5mm

C.5～8mm

D.8～10mm

E.以上都不是

出口口岸栏目应填 ______ 。

A．苏州海关

B．江苏海关

C．上海海关

D．大阪海关

阅读理解。

                                                       Stamps for the white Olympics 

    The Winter Olympics is also called the White Olympics. At this time, many colorful stamps are published

(发行) to mark (标志) the great Games. The first stamps marking the opening came out on January 25, 1932

in the United States for the 3rd White Olympics. From then on, Publishing stamps during the White Olympics

became a rule. (规定) 

    During the 4th Winter Olympic Games a group of stamps were published in Germany in November 1936.

The five rings of the Olympics were drawn on the front of the sportswear. It was the first time that the rings

appeared on the stamps of the White Olympics.

    In the 1950s, stamps of this kind became more colorful. When the White Olympics came, the host

countries (东道国) as well as the non-host countries published stamps to mark those Games. China also

published four stamps in February 1980,when Chinese sportsmen began to take part in the White Olympics.

    Japan is the only Asian country that has ever held the White Olympics. Altogether 145 million stamps were

sold to raise (筹集) money for this sports meet.

    Different kinds of sports were drawn on these small stamps. People can enjoy the beauty of the wonderful

movements of some sportsmen.

1. The White Olympics and the Winter Olympics            . [ ]

A. are the same thing

B. are different games

C. are not held in winter

D. are held in summer

2. The world made it a rule to publish stamps to mark the great world Games            . [ ]

A. after the year 1936

B. after the 3rd White Olympics

C. before the 3rd White Olympics

D. before the year 1932

3. The Winter Olympics is held once            . [ ]

A. every two years

B. every three years

C. every four years

D. every five years

4. Which of the following is true? [ ]

A. Only the host countries can publish stamps to mark those Games

B. Only the non-host countries can publish stamps to mark those Games

C. All countries can publish stamps to mark those Games

D. Japan can't publish stamps to mark those Games

5. What may appear on the stamps of the White Olympics? [ ]

A. Basketball

B. Table tennis

C. Football

D. Skating

如图所示，一质量为m=1kg的小滑块从半径为R＝0.8m的光滑圆弧轨道顶端静止释放。到达圆弧轨道底端时恰好滑上上表面与圆弧轨道底端相切的木板，木板的质量M=1kg。开始静置在水平地面上，小滑块滑上木板后，木板开始向右滑动，最终小滑块以v_m=2m/s的水平速度飞离木板。己知木板高h＝0.8m，小滑块与木板间的动摩擦因数为μ₁＝0.4，木板与水平地面间的动摩擦因数为μ₂＝0.1，g取10m/s²。求：

（1）小滑块滑至圆弧轨道最底端时，圆弧轨道对小滑块的弹力大小；

（2）小滑块飞离木板时木板的速度大小；

（3）小滑块从滑上木板到落至水平地面的过程中，小滑块在水平方向上移动的距离。

下列方法中，利用热传递来改变物体内能的是

A．用热水袋取暖

B．用“搓手”的方法取暖

C．利用钻木取火

D．反复弯折铁丝使其发热