强调满足人类衣、食、住、行等基本需求和教育、就业、娱乐、安全等较髙层次的社会文化需求

There are about 75 brands of microwave popcorn on the market; altogether, they account for a little over half of the money from sales of microwave food products. It takes three minutes to pop corn in the microwave, compared to seven minutes to pop corn conventionally. Yet by weight, microwave popcorn typically costs over five times as much as conventional popcorn. Judging by the popularity of microwave popcorn, many people are willing to pay a high price for just a little additional convenience.
If the statements in the passage are true, which one of the following must also be true

A．No single brand of microwave popcorn accounts for a large share of microwave food product sales.

B．There are more brands of microwave popcorn on the market than there are of any other microwave food product.

C．By volume, more microwave popcorn is sold than is conventional popcorn.

D．More money is spent on microwave food products that take three minutes or less to cook than on microwave food products that take longer to cook.

E．(E) Of the total number of microwave food products on the market, most are microwave popcorn products.

705型试验台做缓解稳定试验时，操纵阀手柄应置（）。

如图所示为氢原子能级示意图，关于能级跃迁下列说法中正确的是

A．处于基态的氢原子，若吸收了能量为12.20 eV光子后，可跃迁到第三能级

B．处于第3能级的氢原子只有吸收1.51 eV的能量才能发生电离

C．大量处于第3能级的氢原子将自发地向低能级跃迁，并发出2种频率的光子

D．当氢原子从高能级向低能级跃迁的过程中，核外电子的动能将增加，氢原子的电势能将减少

颈静脉切迹位于( )

A．颅底骨
B．胸骨
C．锁骨
D．颈椎
E．以上都不对

销售摩托车应纳的增值税为( )元。

A．482800

B．36436

C．486436

D．29467