在用气动PID调节器组成的控制系统中,调节器的输出P出始终大于或等于0.1MPa,其

题型:单项选择题

问题:

在用气动PID调节器组成的控制系统中,调节器的输出P出始终大于或等于0.1MPa,其不可能原因是()。

①喷嘴挡板机构中的喷嘴堵塞

②通负反馈波纹管的恒节流孔堵塞

③喷嘴挡板机构中的恒节流孔堵塞

④通正反馈波纹管的恒节流孔堵塞

⑤给定波纹管破漏

⑥测量波纹管破漏

A.①②③⑤

B.③④⑤⑥

C.②③④⑥

D.②③④⑤

考点:船舶电气与自动化船舶反馈控制系统基础船舶反馈控制系统基础题库
题型:单项选择题

在横线上填上“>”“<”或“=”.

280×5______260×6

57×200______570×20.

题型:单项选择题

写出下列元素的符号或名称.

氢______碳______镁______铜______磷______

O______N______K______Zn______Ag______

题型:单项选择题

胆道闭锁Ⅰ型( )

A.肝门部闭锁,肝外胆道有或无腔隙
B.肝管闭锁,肝外胆道呈一纤维索带
C.胆总管闭锁。肝外胆管呈一盲袋,内含胆汁
D.胆总管正常,肝内胆管扩张
E.胆总管呈囊状扩张

题型:单项选择题

Reading comprehension.

     Holiday Inns and McDonald's, both saw unmatched growth in the 1960s. Their growth opened another

direct business operation-franchising (特许经营).

     These operations have the same general pattern. The franchisor, the parent company, first establishes a

successful retail (零售) business. At it expands, it sees a profit potential in offering others the right to open

similar business under its name. The parent company's methods and means of identification with consumers

are included in this right. The parent company supplies skill, and may build and rent stores to franchisees.

For these advantages the franchisee pays the franchisor a considerable fee. However, some of the advantages

and disadvantages are different.

     By extending a "proven" marketing method, a parent can profit in several ways. First, the franchisee's

purchase price gives the parent an immediate return on the plan. Then the sale of supplies to the franchisee

provides a continuing source of profits. As new businesses are added and the company's reputation spreads,

the value of the franchise increases and sales of franchises become easier. The snowballing effect can be

dramatic. Such growth, too, brings into play the economies of scale (规模经济). Regional or national

advertising that might be financially impossible for a franchisor with 20 franchises could be profitable for one

with 40.

     The parent, then, finds immediate gains from the opportunity to expand markets on the basis of reputation

alone, without having to put up capital or take the risk of owning retail stores. Added to this advantage is a less

obvious but material one. Skilled, responsible retail managers are rare. People who invest their capital in

franchises, through, probably come closer to the ideal than do paid managers. In fact, the franchisee is an

independent store operator working for the franchisor, but without an independent's freedom to drop supplies

at will. Of course the factory's costs of selling supplies are less. But also certainly the franchisee buying goods

that have had broad consumer acceptance will not casually change supplies, even when the contract permits.

If the hamburger is not what the customer expected, they may not return. Having paid for the goodwill, the

franchisee won't thoughtlessly destroy it.

     Franchising may give you the idea that as a franchisor, you need only relax in the rocking chair. Franchising,

however, has problems to be solved.

1. Franchising refers to a business operation in which a successful parent company _____.

A. sells name-brand goods to a private investor

B. rents proven ideas and techniques for investment

C. sells the right, the guidance to a business under its name

D. takes no advertising responsibility for individual investors

2. The advantages of franchising to the parent company are all the following EXCEPT _____.

A. an immediate investment return

B. the ownership of additional retail stores

C. the profit from the sale of supplies

D. the possibility of profitable advertising

3. The passage mainly tells the reader _____.

A. the advantages and disadvantages of franchising

B. the benefits of franchising to the franchisor

C. the unmatched economic growth in the 1960's

D. some regional and national business operation

4. What will the author probably discuss after the last paragraph?

A. More advantages of franchising.

B. Risks of investment besides franchising.

C. The standard of consumer acceptance.

D. Negative aspects related to franchising

题型:单项选择题

乙醇、汽油等易燃物品的保存场所,应注意(),并远离火源。

A.封闭、避光、恒温

B.封闭、避光、保温

C.通风、透光、恒温

D.通风、透光、低温

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