以下有关丁型肝炎病毒(HDV)特性描述中错误的是A．HDV为缺陷病毒 B．HDV只有

As we all know, eating habits are different in different countries. The Chinese have a      . “Eat good things for breakfast, eat a big meal for lunch, but eat        at dinner.” Many Americans agree that one should start the day with a good breakfast, but their       about lunch and dinner are different.

Most Americans only give       a short time for lunch. So they eat a small lunch. After work they will have more time to eat a big dinner. Talking about their day with all the family is a great way to take a good rest after a long, hard day of work.

Eating at restaurants is also different. In China, people like to talk and laugh while     . Very often you can hear people talking and laughing       , and they are just having a good time. In America it is not like this. If someone is talking too loudly at table, the manager of the restaurant may       and ask them to be quiet. After dinner, it’s thought quite rude if you leave       you finish eating. You are expected to stay and        around the dinner table.

So if you want to be       , there’s an English saying, “When in Rome, do as Romans do.”

引进负压原油稳定装置原油进塔压力应为（）MPa。

A.0.2~0.3

B.0.3~0.4

C.0.4~0.5

D.0.3~0.5

关于阻生牙的概念错误的是（）。

A.阻力来源于邻牙

B.阻力来源于骨组织

C.阻力来源于牙龈

D.常见部位为下颌第三磨牙及上颌第一磨牙

E.只能部分萌出或完全不能萌出

现代包装设计者应努力研究和尊重商品销售地区与顾客的（），使之与现代设计表现手法相协调。

A.文化

B.习惯

C.习俗

D.爱好

行政拘留是最为严厉的治安处罚，其最长期限为不超过20日。 ( )