下列lac操纵子的部分二倍体中，（）是组成型表达。A、lacI+O+Z+/F’lac

All around the world, people drink tea. But tea does not mean the same thing to everyone. In different countries people have very different ideas about drinking tea.

In China, for example, tea is always served when people get together. The Chinese drink it at any time of the day at homes or in teahouses. They like their tea with nothing else in it.

Tea is also important in Japan. The Japanese have a special way of serving tea called a tea ceremony(仪式). It is very old and full of meaning. There is even a special room for it in Japanese homes.

Another tea drinking country is England. In England, the late afternoon is teatime. Almost everyone has a cup of tea. The English usually make tea in a teapot and drink it with milk and sugar. They also eat cakes, cookies and little sandwiches at teatime.

In the United States people often drink tea for breakfast or after meals. Americans usually use tea bags to make their tea. In summer, many Americans drink cold tea—“iced tea”. Sometimes they drink iced tea from cans, like soda(梳打).

小题1:How many countries are there in the text to drink tea?

A．Two.

B．Three.

C．Four.

D．Five.小题2: The Chinese always drink tea with _______ in it.

A．nothing

B．sugar

C．coffee

D．milk小题3:The _______ have a special way of serving tea called a tea ceremony.

A．Chinese

B．Americans

C．Japanese

D．English小题4:What time is the teatime in England?

A．The morning.

B．The afternoon.

C．The evening.

D．The late afternoon小题5:The text mainly tells us about _______.

A．tea drinking customs

B．people like drinking

C．tea is important

D．different countries

在-8和10之间插入a₁，a₂，a₃三个数，使这五个数成等差数列，则a₂= ．

（1）实验室选用氯酸钾和二氧化锰制取氧气的发生装置为                 ；该反应的化学方程式为                   ；若用排水法收集完氧气后，应如何操作                              

（2）实验室制取二氧化碳的发生装置为                     ；收集装置为                   。检验二氧化碳是否收集满的方法是                            

（3）若用B装置制取气体，要使反应随时发生或停止，你应如何改进                              

风池善于治疗外感头痛，其主要依据是（）

A.穴居头部，近治作用突出

B.穴属胆经，肝胆经相表里

C.是足少阳与阳维脉的交会穴

D.具有较强的活血通经的作用

E.具有较强的清利头目的作用

石英晶体振荡器中石英晶体的作用是（）。

A.作为感性元件的振荡回路

B.作为串联谐振元件的振荡回路

C.作为并联谐振元件的振荡回路