电磁系测量机构为什么不能直接用于交流电的测量？

问题_______の言叶の読み方として最もよいものを、1 2 3 4から一つ选びなさい。

彼は素朴で诚実な性格だが、人を束缚したがる侧面もある。

A．せいじつ　

B．せっじつ　　

C．せじっつ

D．しょうじつ

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? 

具有调理吞噬作用的补体裂解产物是（）。

A.C2b

B.C3b

C.C5b

D.C2a

E.C4a

TADS预报故障轴承的故障类型包括外圈、（）、滚子、其他。

A.前盖

B.端盖

C.后挡

D.内圈

可摘局部义齿的部件包括( )

A．间接固位体
B．冠内固位体
C．Ⅰ杆
D．邻面板
E．以上均是