题干

如图是甲、乙两种固体物质的溶解度曲线。下列说法正确的是

A:甲的溶解度随温度变化比乙小

B:t2℃时甲的饱和溶液的溶质质量分数小于30%

C:t1℃时,甲、乙饱和溶液的溶质质量分数不相等

D:可采用降低温度的方法使乙的饱和溶液变为不饱和溶液

上一题 下一题 0.0难度 选择题 更新时间:2016-03-04 06:58:36

答案(点此获取答案解析)

B

同类题4

阅读理解

    Recently, I experienced a wonderful lesson in how little things still mean a lot. My brother, mother and I live in a very rural district of Hawaii. Our farm is at least a dozen miles from the most basic of services. Therefore, I take weekly trips to COSTCO to get supplies. About a month ago, I finished loading up the car and was about to leave, when a piece of paper caught my eye. I picked it up and read it carefully.

    It was a receipt(收据) from the State Motor Vehicle Division, recording the owner's payment of her Vehicle's Registration fees. At first I thought that I could find the owner. So I waited there for about an hour. Although the receipt had been borne (由……携带) on the wind, where in the busy, crowded parking lot would I find the owner? I looked over the receipt for contact or any personal data, perhaps a license tag(牌照)or telephone number. I checked the date, the fees paid, noted the name of the owner and pocketed the paper. I concluded that the best and easiest step to take was to put the receipt in an envelope and send it to the owner first the next morning.

    By the end of the week, I received a beautiful thank-you letter from a very grateful and happy woman containing a handwritten message and a gift card. In the letter, the woman explained how the wind snatched(夺去) her receipt from a pocket in her car's passenger door. She had searched everywhere for quite some time before giving up.

    It felt great to know I'd helped someone avoid a loss by doing something that at first glance(一瞥) seemed little or even unimportant.