下列有关氧气性质的描述中，错误的是
A．氧气不易溶于水
B．相同条件下，氧气的密度比空气大
C．液态氧无色、无味
D．氧气能助燃
答案：C
题目分析：在通常状况下，氧气是一种无色、无味的气体，不易溶于水；密度比空气大；在加大压强，降低温度的情况下，能变成淡蓝色的液体；具有助燃性。选C。
点评：识记内容，难度不大，但氧气是只要的知识点，同学们要牢固掌握。
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| Many years ago, my dad was diagnosed with a heart disease. He had to be 1 to the hospital unexpectedly and was unable to work at a(n) 2 job. Wanting to do 3 to keep himself busy, he decided to 4 to work at the local children hospital and 5 up working with the sick children. A girl there had a(n) 6 disease that paralyzed (瘫痪) her from the neck down. She couldn't do anything, and was very 7 . My dad started visiting her in her room, 8 paints, brushes and paper. He 9 the paper up against a backing (衬垫物), 10 the paintbrush in his mouth and began to paint. 11 his head would move. He would visit her 12 he could and paint for her. All the 13 he would tell her, "you can do anything you make up your 14 to. " _15 , she began to paint using her mouth. Soon after, the little girl left because the doctors 16 there was nothing else they could do for her. My dad also left for a while because he became ill. Some time later, my dad 17 and returned. One day while working there he 18 the front doors open. In came the little girl who had been paralyzed, and at this time she was walking. She ran 19 over to my dad and hugged him really tight. She gave my dad a picture she had done using her hands. At the bottom there was a sentence 20 , "Thank you for helping me walk. " My dad, who died just a few months after the little girl gave him the picture, loved every single child in that hospital. | |||
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