题目

核酸是细胞内携带遗传信息的物质，以下关于DNA与RNA特点的比较，叙述正确的是： A．在细胞内存在的主要部分相同                 B．构成的五碳糖不同 C．核苷酸之间的连接方式不同                   D．构成的碱基相同 答案：B                               H(10 分)   People in developed countries usually get their drinking water from a faucet (水龙头) or a bottle. But finding safe drinking water can be rather d 1  in developing countries. People in India,for example,often drink polluted water,which can lead to illness or even d 2. But one Indian company,Sarvajal,has i 3  a great machine: the “water ATM”. Sarvajal's water-filtering (水过滤) network has already p 4  clean water in more than 130 places. Many of these places are small v 5. The water ATM is new and important part of Sarvajal's business.   How do these water ATMs w 6 ? First,local workers filter water using Sarvajal's equipment (设备) .Then workers s 7  the clean water to the ATMs and sell prepaid (预付费) cards to local people. Then they can e 8  get water from the ATMs with the cards.  Thanks to Sarvajal's network and water ATMs,clean water is now a 9 to over 70 ,000 people in India. It makes sense that in one of the local 1 10 Sarvajal means “water for all”.1. d   2. d   3. i    4. p    5. v  6. w   7. s   8. e    9. a   10. 1