黄铜是由铜和()组成的合金。
参考答案:锌
向盛有一定淀粉溶液的试管中加入适量的唾液淀粉酶,37℃水浴保温后,加入适量的0.1g/mL的NaOH和0.05g/mL的CuSO4溶液,摇匀后,观察试管内溶液变化应该是[ ]
A.产生砖红色沉淀
B.溶液呈现蓝色
C.溶液呈现紫色
D.溶液不变化
If someone says "You played very well in the game today. " one may respond with "______"
A. Yes, I do think so. B. I was lucky you like it.C. Thank you. So did you. D. Do you really think so