十二指肠钩虫口囊的特征是（）。 A.背侧前缘有1对板齿 B.腹侧前缘有1对板齿 C.

阅读短文，根据短文内容回答问题。

     Chinatown is the name given to an area in the middle of London. It is just between Leicester Square

and Shaftsbury Avenue. Gerrard Street is at the center and is the most important street in the area. There

is a large Chinese community (社区) with a lot of Chinese restaurants, Chinese supermarkets and shops

in this street.

     In the 1950s, it was a poor area and everything was very cheap. At the same time, the world rice

market changed and thousand of farm workers in Hong Kong lost their jobs. They began arriving in

London to look for work. They found jobs in the restaurants in this area. Many British people like Chinese

food, and the restaurants were popular. 

    These restaurant workers often worked 17 hours a day and had no time to learn English. As more

Chinese arrived, more shops and businesses grew up. Wives came and joined their husbands and children

came and joined their fathers. The community grew, and Chinatown was born.

    In the 1970s and 1980s, British-born Chinese started to have a better education and this brought

economic (经济的) success to the area. Many families moved out of Chinatown, and there was more

space for businesses. Gerrard Street become a street only for visitors and was soon a popular place for

tourists.

    Now everyone knows about London's Chinatown. During the Chinese New Year, the streets are seen

with flags and thousands of Chinese go into the streets. For most of the year, though, Londoners and

tourists go there mainly for the food in the Chinese restaurants. They best restaurants are the ones where

the Chinese eat.

1. Is this Chinatown in the middle of London?

2. Was the area rich or poor in the 1950s?

3. Why did the restaurant workers have not time to learn English?

4. When did British-born Chinese start to have a better education?

5. What are the main points about Chinatown in this passage? 

关于HCO₃ˉ重吸收的叙述，错误的是

A．主要在近球小管重吸收
B．主要是以CO₂的形式重吸收
C．需要碳酸酐酶的帮助
D．HCO₃ˉ先于Cl^-的重吸收
E．与H⁺的分泌活动无关

某场地的建筑采用桩基础，其土层分布和标贯击数如表，地下水位埋深5.0m，地震设防8度，设计地震分组第一组，计算液化指数接近（）。

A.20

B.23

C.18

D.12

我国的原始社会，西安半坡氏族是黄河流域母系氏族公社（）文化的一个典型代表。

A.仰韶

B.大汶口

C.龙山

D.良渚