从下列物质中选择填空（填序号）：①甲烷②食盐③浓硫酸④氨水⑤氮气。 （1）可用做

两个异号点电荷的质量分别为m₁、m₂，电荷量分别为Q₁、Q₂，相距为d，在库仑力作用下（不计万有引力）各自绕它们连线上的某一点，在同一水平面内做匀速圆周运动，已知静电力常量k，则它们的总动能为（　　）

A．k

B．k

C．k

D．k

自汗多因

A．阳气暴脱于外

B．气虚卫阳不固

C．阴虚阳亢于上

D．邪正相争剧烈

E．血虚阴亏于里

Teenagers will be told to "stand up for their elders" on public transport — or risk losing their right to free travel.

London Mayor Boris Johnson will declare plans today to make youngsters sign a “courtesy pledge"  (文明宣言) to promise to behave in a respectful manner when travelling in the capital. The three-point pledge states that they will give up their seats to the elderly, pregnant and disabled; keep from using offensive or threatening language; and be courteous and polite to fellow passengers and staff.

Those who refuse, or are caught behaving in a loutish manner, will have their free travel passes removed. The plan — a key part of Mr. Johnson's re-election bid— will initially affect the 400,000 ll-to-15-year-olds in London who qualify for free travel cards, but Tory sources believe the idea could be used across the country.

A Conservative insider said: "The plan corresponds perfectly with the push to create a Big Society. It is about changing culture and expectations around behavior to improve the atmosphere on buses and trains for everyone."

Speaking before today's launch, Mr. Johnson said he was determined to deal with the anti-social behavior of a "minority of youngsters" on public transport. "When I was a boy, I was taught to stand up for those less able to, "he said. "Youngsters enjoy the privilege of free travel, which is paid for by Londoners, but they have to understand that with that privilege comes responsibility. Anyone who abuses this privilege will have it taken away, and will have to earn that right bach ."

Teenagers found guilty of a serious violation of the new behavior rules will lose their travel passes, and will have to carry out unpaid community work to earn them back.

Mr. Johnson is also introducing a "two strikes and you're out" policy to deal with repeat offenders, under which those committing a second serious violation of the rules will lose their travel rights permanently.

小题1:Which of the following is NOT the content of the "courtesy pledge"?

A．Teenagers should give up their seats to the old.

B．Teenagers shouldn't talk with strangers in public.

C．Teenagers mustn't use aggressive language in public.

D．Teenagers must be polite to people on public transport.小题2:What does the underlined word "loutish" in Paragraph 3 most probably mean?

A．rude

B．stupid

C．polite

D．calm小题3:According to Mr Johnson,____________.

A．youngsters should know duty comes with benefit

B．youngsters shouldn't use the privilege of free travel

C．anyone shouldn't make money with the privilege

D．youngsters should do some unpaid community work小题4:The worst punishment teenagers can face is____________.

A．to sign an agreement

B．to work in the community

C．to be fined

D．to lose their travel passes forever小题5:Which of the following can be the best title for the passage?

A．London Mayor Boris Johnson is a great person

B．The plan corresponds perfectly with the Big Society

C．Be polite and stand up for your elders or lose free travel

D．The "courtesy pledge” has been used across the country

如果市场不是有效的，基金管理人会（）。

A．买入价值低估的股票，卖出价值高估的股票

B．买入价值低估的股票和价值高估的股票

C．卖出价值低估的股票和价值高估的股票

D．卖出价值低估的股票，买入价值高估的股票

串联电阻中，电阻大的分得的压降较____。