青春痘

产权登记应遵循（）的原则。

A.统一政策，统一实施

B.统一政策，分别实施

C.不同政策，统一实施

D.不同政策，分别实施

Visitors to this country are normally admitted for six months, but foreign students can usually stay for one year. They must (52) an educational institution, and they are required to study for a (53) of fifteen hours a week on a daytime course. Prospective students have to show that they can afford their studies, and that they have sufficient (54) resources to support themselves (55) in this country.

In order to work here the foreigner needs a work permit, (56) must be applied for by his prospective employer. The problem here is that the Department of Employment has the right to grant or (57) these permits, and there is little that can be done (58) it; it would be extremely unwise for a foreign visitor to work (59) a permit, since anyone doing so is liable to immediate deportation (驱逐出境). There are some people from the European countries, who are often given (60) residence permits of up to five years. Some other people, such as doctors, foreign journalists, authors and others can work without permits, and foreign students are normally allowed to (61) part-time jobs while they are studying here.

53().

A.natural 

B.financial 

C.human 

D.economical

血液能不停地在血管、心脏组成的封闭的管道内循环流动，其动力来自（　　）

A．心脏有节律的收缩和舒张

B．动脉的收缩和舒张

C．静脉的收缩和舒张

D．骨胳肌的收缩和舒张

核电站将______能最终转化为电能．它常建在海边，其原因之一是需要大量的水作为汽轮机的冷却剂，这利用了水的______较大．

肾脏调节血液pH是通过（）

A.Cl^-的重吸收

B.Na⁺-K⁺碱交换

C.HCO^-₃的重吸收

D.排泄固定酸保留并维持血中碱储

E.以上都是