试述行政许可的概念、特征、分类及其作用。

根据短文内容及首字母提示，填写所缺单词。

       Children's education is changing very fast today. In the past, teachers made children s  1   quietly for

hours. They made them r  2   all kinds of things. The children had to go on r  3   things again and again

until they knew them "by heart". Today, many teachers wonder if it is p  4   to make children learn at all.

They say you can o  5   help them learn. They say you must let children learn and discover things for t  6  . But for some of the children, school is a kind of p  7   they can't escape(逃亡) from. They are there only b  8   their parents make them go. They get out of the classroom as soon as the teachers let them leave.

Many of them want to find j  9   but the law(法律) will not let them work until they reach a certain(一定的) age. And so, they have to stay in school. O  10   they do not learn anything at all and hate every

moment.

临床上使用的基托材料主要为热凝和自凝基托材料两种，在组成，性能及应用上都不同

自凝塑料在临床使用时最佳操作的时期一般是在（）

A.湿砂期

B.糊状期

C.粘丝期

D.面团期

E.橡胶期

下列哪项不是流行腮腺炎的表现

A．发热、纳差、乏力

B．腮腺肿大以耳垂为中心

C．呈弥漫性肿大，边界不清

D．腮腺红、肿、热、痛

E．咀嚼和进食酸性食物时疼痛加剧

以下属于学校团体辅导基本程序的有（）。

A.选题

B.实施

C.资料收集

D.评估

E.跟踪

有患侧腋窝淋巴结肿大 * * 疼痛的疾病是( )。

A．急性 * * 炎
B． * * 脂肪瘤
C． * * 囊性增生病
D． * * 纤维腺瘤
E．乳管内 * * 状瘤