重大事故隐患评估费用由______支付。A．被评估单位B．评估单位C．当地政府财政D

如图所示，MN、PQ是平行金属板，板长为L，两板间距离为d，在PQ板的上方有垂直纸面向里的匀强磁场．一个电荷量为q、质量为m的带负电粒子以速度v₀从MN板边缘沿平行于板的方向射入两板间，结果粒子恰好从PQ板左边缘飞进磁场，然后又恰好从PQ板的右边缘飞进电场．不计粒子重力．试求：

（1）两金属板间所加电压U的大小；

（2）匀强磁场的磁感应强度B的大小．

在病例对照研究中，通常用以下方法选择对照，除（）。

A.不考虑对照所患疾病

B.与病例的某些特征相一致

C.从病例的邻居或亲属中选取

D.从病例所来自的人群中的非病例中随机选取

E.从病例所来自的医院中的其他病例中随机选取

Love is a telephone which always keeps silent when you are longing for a call, but rings when you are not ready for it. As a result, we often miss the sweetness from the other end.

Love is a telephone which is seldom program-controlled or directly dialed. You cannot get an immediate answer by a mere "hello", let alone go deep into your lover's heart by one call. Usually it had to be relayed by an operator, and you have to be patient in waiting. Destiny(命运) is the operator of this phone, who is always irresponsible and fond of playing practical jokes to which she may make you a lifelong victim intentionally or unintentionally.

Love is a telephone which is always busy, When you are ready to die for love, you only find, to your disappointment, the line is already occupied by someone else, and you are greeted only by a busy line. This is an eternal regret handed down from generation to generation and you are only one of those who languish for（因…受煎熬） followers.

Love is telephone, but it is difficult to seize the center time for dialing, and you will let the opportunity slip if your call is either too early or too late.

Love is a telephone which is not always associated with happiness. Honeyed words are transmitted by sound waves, but when the lovers are brought together, the phone serves no purpose that many lovers observe that marriage is the doom of love.

Love is a telephone which, when you use it for the first time, makes you so nervous and excited that you either hold the receiver upside down or dial the wrong number. By the time you've calmed down, you will beat a loss to whom you should make the call.

Love is a telephone which often has crossed lines. And this usually happens to you unexpectedly. Your time will either cross or be crossed. Both cases are referred to as "triangle". Fortunately, all such occurrences are transient(转瞬即逝的).

小题1:What is the best title of the passage?

A．Love is transient

B．Love is permanent

C．Love is a telephone

D．What’s love in life小题2:Which statement has the closest meaning to the underlined sentence?  

A．"all shall be well，Jack shall have Jill。“（有情人终成眷属）

B．A lifelong love is not only romantic but also practical

C．Love is all we have in life

D．Beauty is in the eyes of beholder小题3:Which is the synonym with the underlined word ”doom”?

A．monument

B．final end

C．key point

D．substitute小题4:In which part can this passage probably be found ?

A．advertisement

B．financial

C．emotion

D．lottery

发生绞窄性肠梗阻的原因为（），（），（）等。

去除残留于工件表面上的水洗型渗透剂的最好方法是（）

A、将零件浸入水槽中清洗

B、在水龙头下用流水冲洗

C、在热水中煮或用蒸汽喷洗

D、用软管和喷嘴产生有一定压力的水柱喷洗