题干

紫色水萝卜块根细胞的液泡中含有呈紫红色的花青素,将块根切成小块放入清水中,水的颜色无明显变化.若进行加热,随着水温的增高,水的颜色逐渐变红,其原因是(    )

A:细胞壁在加热的过程中受到破坏

B:水温增高,花青素的溶解度加大

C:加热使膜失去了选择透性

D:加热使细胞壁失去了选择透性

上一题 下一题 0.0难度 选择题 更新时间:2018-02-02 03:30:26

答案(点此获取答案解析)

C

同类题2

阅读下列短文,从各题所给的四个选项(A B C D)中,选出最佳选项。

B

    Do you shop online with websites like Taobao? The money you pay doesn't go directly to the seller. Instead, it goes through Alipay, which keeps your money for a while. After you receive your goods and click the "confirm receipt" button, Alipay then gives the money to the seller.

    The process is called "third party online payment". There is a transfer station, or a third account, between sellers and buyers to make online shopping safe. Buyers don't need to worry about paying for goods and then receiving nothing. Sellers also get rid of the risk of receiving no money after sending out goods.

    These transfer stations are usually set up by payment service companies such as Alipay, Tenpay and Yeepay. Among them, Alipay is the biggest in China. It has more than 270 million active users, according to Xinhua.

    While most online sellers and shoppers like the third party online payment system, banks are not very happy. That is because companies like Alipay are fighting over money with the banks. Users can invest in financial products through Alipay and make money. Thus lots of people choose to put money in Alipay rather than in banks.

    But WeChat payment is not the same. WeChat doesn't have its own account. When paying through WeChat, the buyers' money goes directly to the sellers. That's why so many people are excited about receiving and handing out "red envelopes" or gift money to their friends on WeChat.

    Whether Alipay or WeChat payment, they are all trying to attract more users and make online shopping easier. These two companies are also promoting payments through fingerprints. New payment methods such as quick response codes have become popular too.