在下面语段的横线上依次填入关联词语，最准确的一项是（    ）

      在一定的条件下，科学知识之所以正确是因为经过了实践的检验。________条件变化了，原有的科学知识会被人们用新的实践去检验，________会被修改和发展成新的科学知识。但人们之所以要不断学习________因为原有知识统统“过期变质”，________是因为新条件下产生的新知识能使人们的知识、思维和智慧更上一层楼。

    When China's astronaut Zhai Zhigang carried out the spacewalk on September 27, he was wearing a spacesuit developed by Chinese scientists. Being worth more than 30 million yuan, the Feitian (飞天) spacesuit is not ____ordinary one.

    It ____（take）Chinese scientists four years to develop it. But what is special about the suit? First Let's take a look at why____（astronaut） need to wear spacesuits.

    When you visit a world with little or no atmosphere, not____(wear) a spacesuit, the following things would happen:

    You would become unconscious within 15 seconds because there is no oxygen.

    Your blood and body fluids(液体) would “boil” and then “freeze” ____ there is little or no air pressure.

    You would receive various types of radiation.

    You could____(hit) by dust or rock that moves at high speeds.

So, to protect you____these dangers, a spacesuit must:

    Have a pressurized atmosphere;

    Give you oxygen;

    Keep a(n) ____(comfort) temperature;

    Let you see clearly and move easily.

    The Feitian suit did all that and what it ____（do）made it like a mini-spaceship in____the astronaut stayed alive in outer space and carried out tasks.

在“测定小灯泡额定功率”的实验中（小灯泡标有“3.8V“字样，灯泡的电阻约为12Ω）：