以下关于消声器消声原理论述哪个不正确（）。 A.排气喷流消声器是一种利用吸声材料消声

根据下列句子及所给首字母，写出空缺处各单词的正确形式。

1. This hat will give p_______ against the hot sun.

2. I would a_______ it if you would turn the music down.

3. We, human beings should protect w_______ for our own existence.

4. In class you should pay a_______ to what your teacher is saying.

5. My father was warned by the neighbors that we were in d_______.

6. The dog looks very f_______, but it is very gentle really.

7. There are many kinds of i_______ in the world, a bee is one kind of them.

8. You will e_______ your health if you work so hard.

9. I was at a complete l_______ as to how to find the money in time.

10. The city of Yuyao has _______ in holding the 11th Exhibition of Plastics.

牙周病的预防措施不包括

A．以健康教育为基础，提高自我口腔保健和维护牙周健康的能力
B．养成良好的口腔卫生习惯
C．提高宿主的防御能力
D．进行有效系统的牙周治疗
E．维持牙周治疗的疗效

如图所示，物块A放在倾斜的木板上，已知木板的倾角α分别为30°和45°时物块所受摩擦力的大小恰好相同，则物块和木板间的动摩擦因数为（　　）

A．

B．

C．

D．

以下对广东农村信用社办理单位验资账户销户业务的主要风险点描述错误的是（）

A.审核客户撤销账户的材料或证明是否齐全，手续是否完备

B.验资不成功的验资户撤销时，应将资金原路退回给投资人，对于以转账现式缴存资金的允许提取现金

C.验资不成功的验资户撤销时，应逐笔原路退回缴资资金，最后一笔资金的退回时应选择销户

D.注册验资成功的，直接将验资户转基本存款户，如基本存款户在他行的资金款项必须转入其对应的基本存款账户

简述教育行政执法的特征。