硫酸铵作为最常用的盐析剂优点是
A. 盐析能力强
B. 溶解度大
C. 稳定蛋白
D. 无腐蚀性
Why was Rob Richardson annoyed?
A. Technology has caused a severe smartphone addiction.
B. Students did not pay attention while he was lecturing.
C. He failed to earn a reward for creating a useful app.
D. Students ignored classes and checked their phones.
What can the app Pocket Points do?
A. Prevent students from using their phones too often.
B. Reward students who do not use their phones on campus.
C. Provide students with easy access to online stores.
D. Warn students who look at their phones in class.
How many students are using the app now?
About 500,000.
B. About 100, 000.
C. About 1,200.
D. About 10,000.
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