题干

下列为探究某种加酶洗衣粉所需要的最适温度实验方案,其中正确的是(    )

A:取一系列不同温度、其他条件相同的水,加入相同的污物及等量加酶洗衣粉,看哪一个温度中酶的效果最好

B:在不同温度的水中,加入不等量洗衣粉,看哪种效果好

C:将加酶洗衣粉加入30℃水中不如加到45℃的水中洗涤效果好,说明45℃为最适温度

D:将加酶洗衣粉与普通洗衣粉分别加入37℃的水洗涤同样的污物,发现加酶洗衣粉效果好,说明加酶洗衣粉的最适温度为37℃

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A

同类题5

根据短文内容的理解,选择正确答案。   

    Tanzania(坦桑尼亚)is a country which has a lot of animals, such as gnus(角马), lions, cheetahs(猎豹, elephants, giraffes, crocodiles and so on. Every year, many people in the world travel to this African country to watch the animals closely. But do you know how they travel?

    By bus—This is the most common way. When people get on a bus, they'll find that the bus is a little strange. It is different from the buses we often see. There are no big windows at all, but some small windows. And it looks like a cage. What are they used for? Oh, people can use it to watch animals, especially those dangerous animals, and take photos. We know that people are most interested in the lions. So when two buses meet, the drivers will stop and ask each other whether they have found lions.

    By boat—We can often see many people are in a boat, enjoying the beautiful scene along a river of a lake, and they can also enjoy hippos(河马)and crocodiles from a nearer distance.

    By hot balloon(热气球)—In the early morning, when the sun is beginning to rise, a large hot balloon is also starting its journey. Taking a hot balloon makes most of the travelers excited. After some time, the balloon will land in a certain place, and the waiters will serve people a delicious and special breakfast. But the cost of taking a hot balloon is also very high. A person should pay 400 dollars for an hour's trip.