蒸馒头、炸油条时常用到一种白色固体物质，它与发酵过程产生的酸反应并引起发泡作用，这种白色物质是
A．NaOH
B．NaHCO3
C．Ca(OH)2
D．NaCl
答案：B
题目分析：中和发酵过程产生的酸，并能引起发泡作用，说明该物质与酸反应时生成了气体。
A、氢氧化钠具有极强的腐蚀性，不能用于食品工业，且与酸反应不产生气体，故A错误；
B、碳酸氢钠可以与酸反应生成二氧化碳气体，符合题意，故B正确；
C、氢氧化钙具有腐蚀性，不能用于食品工业，且与酸反应不产生气体，故C错误；
D、氯化钠与酸不反应，故D错误。故选B
点评：物质的性质决定物质的用途，完成此题，可以依据常见物质的性质进行解答。
Language is colourful. There are many with heart. One of them is to “lose your heart” to someone. When that , you have fallen in love. if the person who “won your heart” does not love you, you are to have a “broken heart.” In your , you think that the person you loved is “hard-hearted,” and in fact, has a “heart of stone.” You may decide to “pour out your heart” to a friend. Telling someone about your personal can often make you feel better. If your friend does not to understand how painful your broken heart is, you may ask her to “have a heart.” You are asking your friend to show some sympathy (同情) for your . Your friend “has her heart in the right place” if she says she is sorry for you feel. If your friend says, “My heart bleeds for you”, she means the . She is a cold-hearted person who does not really your situation. When you are feeling , “your heart is in your mouth.” You might say, for example, that your heart was in your mouth when you asked a bank to lend you some money to a new house. If that bank says to you, do not “lose heart.” Be “strong-hearted.” Sit down with the banker and have a “heart to heart” talk. Be open and honest about your situation. The bank may have a “change of heart” and agree to lend you the money. Then you could worrying and “put your heart at rest.”
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