题干

下列有关海水淡化的方法不可行的是(  )


A:加明矾使海水中的盐分沉降,然后过滤以获得淡水

B:利用太阳能将海水蒸馏淡化

C:在一定条件下将海水凝固以获取淡水

D:用超滤膜使海水中较小的水分子通过,而较大的溶质微粒不能通过从而获得淡水

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答案(点此获取答案解析)

A

同类题4

阅读下列短文, 从给的四个选项 (A、B、C和D) 中, 选出最佳选项。   

    More over smart phone, the intelligent watch is about to take your spot as the latest hi­tech current, allowing wearers to glance at messages and even take calls without touching their phones. The i'm Watch, available since 2011, is the flagship product of an Italian company—i'm. This smart watch is an assist to the smart phone, with which it can communicate by Bluetooth wireless technology. It means you can leave your phone in your pocket as you answer or reject a call, review e­mails or read updates from friends on Twitter or Facebook.

    The i'm Watch also has its own applications, such as i'm Sport, which links with a heart rate detector (检测器) to allow a runner to check his pulse. Such functions already exist in specialized sports watches but not on watches that are linked to smart phones.

    With a square shape, a 3.8­centimeter touch screen and various colors, the i'm Watch sells for a minimum of 300 Euros ($390) for the basic model and prices climb to 16 000 Euros for a luxury model in silver or decorated with diamonds.

    So far, the watch has already found 30 000 buyers, 80 percent of whom are men aged 25 to 50. “Seventy percent are iPhone users, 25 percent Samsung and the rest are other telephones using Google's Android operating system,” said Massimiliano Bertolini, a manager of the company, which aims to sell more than 200 000 watches this year. The company's target market is the person who is always glued to his smart phone, even in meetings or at the movies, or people who wish to keep an eye on their heartbeat during exercise. They will especially target women with advertisements emphasizing its design rather than its technology.