多级汽轮机的优越性不包括（）。 A.提高单机功率，蒸汽在汽轮机中具有较大的质量焓降

根据我国合同法规定，甲公司与乙融资租赁公司签订了融资租赁合同、那么乙公司的下列行为不属于违约行为的有：( )。

A．出卖人不履行买卖合同义务，甲公司行使索赔权，但乙公司以业务繁忙为由，不愿协助的

B．根据甲公司对出卖人、租赁物的选择订立的买卖合同，未经甲公司同意，乙公司变更与甲公司有关的合同内容的

C．甲公司自行确定租赁物，乙公司对租赁物的选择未进行干预，但租赁物不符合使用目的的

D．乙公司不履行租赁物的维修义务的

Insurance companies provide a service to the community by protecting it against expected and unexpected disasters. Before an insurance company will agree to insure anything, it collects accurate figures about the risk. It knows, for example, that the risk of a man being killed in a plane accident is less than the risk he takes in crossing a busy road. This enables it to quote(报价) low figures for travel insurance. Sometimes the risk may be high, as in motor-racing or mountaineering. Then the company charges a much higher price. If too many climbers have accidents, the price rises further. If the majority of climbers fall off mountains, the company will refuse to insure them.

An ordinary householder may wish to protect his home against fire or his property against burglary(入室行窃). A shopkeeper may wish to insure against theft. In normal cases, the company will check its statistics and quote a premium(保险费). If it is suspicious(可疑的), it may refuse to quote. If it insures a shop and then receives a suspicious claim, it will investigate the claim as a means of protecting itself against false claims. It is not unknown for a businessman in debt to burn down his own premises so that he can claim much money from his insurance company. He can be sure that the fire will be investigated most carefully. Insurance companies also accept insurance against shipwreck or disaster in the air. Planes and ships are very expensive, so a large premium is charged, but a reduction is given to companies with an accident-free record.

Every week, insurance companies receive premium payments from customers. These payments can form a very large total running into millions of dollars. The company does not leave the money in the bank. It invests (投资) in property, shares (股票) ,farms and even paintings and stamps. Its aim is to obtain the best possible return on its investment. This is not as greedy as it may seem since this is one way by which it can keep its premiums down and continue to make a profit while being of service to the community.

小题1: The main idea of the first paragraph is that      .

A．insurance companies protect the community against disasters

B．insurance companies often collect accurate figures about the risk

C．insurance companies base their decisions on the risk involved

D．insurance companies charge different prices in the same cases小题2:The insurance company will usually investigate a suspicious claim to    .

A．refuse to quote the insurance fee

B．make sure that the claim is reasonable

C．decide how much the company should pay

D．find out when the accident happened小题3:The underlined word "premises" in Paragraph 2 most probably means"     "

A．land and buildings

B．insurance contract

C．debt papers

D．financial papers小题4:The author’s attitude towards customers’ premium payments being used by insurance companies is __

A．critical

B．doubtful

C．neutral

D．positive小题5:The purpose of this passage is to __

A．explain how insurance companies operate

B．encourage people to invest in insurance companies

C．persuade people to insure against unexpected disasters

D．advise people how to insure their life and property

隋朝，隋炀帝于（）下令重开江南运河。

A.大业六年（610）

B.大业八年（612）

C.大业二年（606）

用于工器械洁治时，应注意

A．器械与牙面、软组织的适应度

B．工作端与牙面的工作角度

C．使用手腕的推拉力

D．洁治方向为垂直、水平、斜向

E．以上都是

说明电缆防火的措施？