交换机利用（）地址构建MAC地址表？A目标IP地址B目标MAC地址C源IP地址D源M

请根据括号中的中文提示、英文释义或句意，写出句中所缺单词，使句子通顺。

小题1:The girl is very healthy because she ___________(很少) eats junk food and exercises more.

小题2:The bus is so ___________(拥挤的) that we have to wait for the next one. How unlucky!

小题3:Zhou Kehua’s girl friend will be put in __________for five years because she also has done something against the law.

小题4:As teachers, we should __________(say again) the important points in class again and again so that some slow students can have a good understanding.

小题5:It is our duty to protect the ____________(环境）because pollution is getting more and more serious.

2009年9 月1日，国务院印发《关于开展_________试点的指导意见》，这有助_____亿农民安心养老。[ ]

A．农业农村发展基础   八           

B．农村医疗救助          九

C．统筹城乡发展力度     八           

D．新型农村社会养老保险   九

下列不应预防性应用抗生素的手术是（）

A.甲状腺癌根治手术

B.腹外疝修补术

C.门静脉高压症，分流术

D.结肠癌根治术

E.主动脉瘤切除血管移植术

电火花是（）放电现象，而大量的电火花汇集形成电弧。

A、短路

B、断路

C、击穿

鲁迅先生说：“中国现代社会的情况，只有实地的革命战争。一首诗吓不走孙传芳，一炮就把孙传芳轰走了。”这里的“一炮”指的是（）

A.武昌起义

B.广州起义

C.北伐战争

D.南昌起义