题干

请认真分析如表关于探究“馒头在口腔中的变化”的实验,若以“唾液”为变量时,则能形成对照实验的两支试管是(    )

试管

加入物质

是否搅拌

保温温度(℃)

试剂

1号

少许馒头碎屑+2mL唾液

搅拌

0

2滴碘液

2号

少许馒头碎屑+2mL唾液

搅拌

73

3号

少许馒头碎屑+2mL唾液

搅拌

37

4号

少许馒头碎屑+2mL清水

搅拌

37

A:1号和2号

B:1号和3号

C:2号和4号

D:3号和4号

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答案(点此获取答案解析)

D

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    I was eight years old then. Looking1I remember the time in a baseball field passing the team that we had just2. We shook their hands and said, ”Good game!”

    It is3to do that when you win! When you lose, you have a tendency(倾向) to slap (拍) the hand-instead of shaking it-and4the ground instead of the eyes. This is not only true for an eight-year-old; it is true for adults, too.

    A few years ago, in a softball league, we lost 15 games! And we thought it was5. But during the “Good game” handshake after each6, I looked each player in the eyes and shook their hands. I couldn't look my opponents (对手) in the eyes and congratulate them on a good7when I was eight. Somehow I took the loss as a8on my self-worth and felt my self-confidence had been slapped;9-I did what most eight-year-olds do and I slapped the opponents' hands, not giving them the satisfaction of a shake. I was wrong to do this. I'm happy today as a(n)10 that I have learned this11: There is something to be said for losing well.

    12it is a baseball game or an important examination, you can13a lot about a person by now they deal with defeat. The person who deals with defeat as an14blow is not allowing the event to define (定义) him, while someone who cannot15defeat is allowing the event to16his self-worth. In my opinion, when you17in something-though it may be18-look at your opponents in the eyes, and shake their hands in a19way as you say, “Good game!”20to allow the event to define your life. You might find yourself winning the next game.