下列药品中，不需要密封保存的是（ ） A．氢氧化钠 B．澄清石灰水 C．浓硫酸

阅读理解。

     The car you buy in the future may be very different from your parents' car. Their car has four wheels,

but your car may have two wings (翅膀). New Scientists Magazine says American Aviation Company is

going to test a flying car.

     The Skycar looks like a red bat mobile (蝙蝠状的可移动物). It seats about four people and has a top

speed of over 600 km per hour. At that speed, a 200-km trip only takes about 20 minutes. It will be able to

take off and land up and down, like a helicopter (直升飞机). During its first test, the Skycar will rise to a

height of 2 meters, hover (盘旋) for one minute, and then land.

    The Skycar is hand-built and cost about $1 million. The company thinks that one day the Skycar will

cost about $60,000.

1. What does the Skycar look like?

    ________________________________________________

2. How long will it take if you take a 360-km trip in a Skycar?

    ________________________________________________

3. What's the top speed of the Skycar?

    ________________________________________________

4. How many people can a Skycar carry?

    ________________________________________________

5. How much will a Skycar cost one day?

    ________________________________________________

有一电流表其内阻为100欧姆，满偏电流为500微安。

（1）若用它改装成量程为2.5A的电流表，应如何改装？

（2）若用它改装成量程为3V的电压表，应如何改装？

17世纪，范海尔蒙特将2.5㎏的柳树种子种于100㎏土中，5年中只浇水，5年后称重，柳树重82.5㎏，土重约99.9㎏，由此得出绿色植物生长所需的物质主要是（　　）

A．二氧化碳

B．水

C．氧气

D．无机盐

作为热压灭菌法灭菌可靠性的控制标准是

A．F₀值
B．F值
C．D值
D．Z值
E．N值

国防法规所保护的国防利益，是关系国家安危的重大利益，因而对危害国防利益的犯罪行为实行比较（）的处罚。

A、轻微

B、严厉

C、一般

D、普通