判断下面的读音是否正确。

蹚过去(dānɡ ɡuò qù)(　　)

在C+O₂CO₂反应中，　____ 份质量的碳与　____ 份质量的氧气反应生成　____ 份质量的二氧化碳，反应中各物质的质量比为（化成最简）____ ．

写出加下划线词语的反义词。

①它含有丰富的铁和镍，所以才会这般坚硬。____

②它沉默着，那么安静。____

③我们真想知道它过去的行踪。____

④它是一块沉睡的物体。____

    Want to be an astronaut?Then“study hard，stay healthy and have perseverance”!

    This is what Chinese astronauts Fei Junlong and Nie Haisheng said in Hong Kong．Fei，Nie and leading engineers of Shenzhou VI visited Hong Kong from November 27 to 30，2010．

    They talked with primary，secondary and college students．Kids were interested in the astronauts' space lives．They asked questions like “Did you see the Great Wall from space?”Fei and Nie said they didn't see the Great Wall．But they felt excited when they passed over China，including Taiwan．The Taiwan Island looks very beautiful，like jade．

    Young people wanted to know how the astronauts developed(发展)their careers(职业)．“How did you decide to be astronauts when China's space industry is still at the beginning?”spoke a young woman．The astronauts said it was because of their love of flight and the need of the nation．They said their love of flight could be seen from their children's names．Nie's daughter is named Nie Tianxiang，which means“flying up high”．Fei's son is called“Fei Di”，which sounds like“Feidie”，meaning UFO．

下列划线词解释有误的一项是  (       )