对幅值和转速都在变化的椭圆形旋转磁场，可以用分解法分解为（）。 A.两个正向圆形磁场

填空。

     Finally, we arrived at the World Park. The sky was blue and __1__ was beautiful. We became very

 __2__ when we saw the model Eiffel Tower from the coach! It is made of __3__ and really tall. When

  the coach stopped, we all got off quickly. Kitty and I didn't feel __4__ any more. We just wanted to go

  into the park and enjoy__5__ . Then the real __6__ came, like bombs under the ground. The earth

 started to __7__ . People ran in all __8__ . They did not know where to go. Some people ran out of the

  shopping __9__ . I tried my best to run to the street too. People were running wildly while pieces of glass

  and bricks were __10__  down. Then the walls began to come down, too.

下列事件：①明天是晴天；②在图形的旋转变换中，面积不会改变；③同时掷两个骰子，点数和大于13；④买一张 * * 中特等奖．属于是不确定事件的有（　　）

A．4个

B．3个

C．2个

D．1个

渐尖、急尖、尾尖、钝尖、微凹、倒心形都属于叶的尖端形状的描述。( )

有关薄束的说法正确的是（）

A.位于脊髓前索

B.传导同侧上肢浅感觉

C.起自对侧脊髓后柱固有核

D.只见于脊髓胸、腰段

E.传导同侧下肢本体觉

建筑工程的厕浴间、厨房及有防水、防潮要求的建筑地面与木、竹地面应有建筑标高差，其标高差必须符合设计要求。( )