问题
单项选择题
我国现行的水质标准对牙齿来说适宜的水氟浓度应是（）
A.0.5～1ppm
B.1ppm
C.1～1.5ppm
D.1.5～2ppm
E.＞2ppm
答案
参考答案：A
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我国现行的水质标准对牙齿来说适宜的水氟浓度应是（）
A.0.5～1ppm
B.1ppm
C.1～1.5ppm
D.1.5～2ppm
E.＞2ppm
参考答案：A
| 读一读，选择合适的问句。 | |
B: Yes. I can see many animals. A: 2.______________________ B: The tigers are fighting. The lions are sleeping. A: Can you see any kangaroos? B: Yes, I can. A: 3.____________________ ? B: The mother kangaroo is jumping. The baby kangaroo is sleeping. A: I like kangaroos very much. 4.__________________________? B: Yes, I do. |