⑴How's the weather today?____ A. Yes, it is.
⑵Is it rainy?____ B. Sure. Here you are.
⑶Can I have some hot water?____ C. It's snowy.
“绿叶在光下制造有机物”实验的正确顺序是( )
①把叶片放在装有酒精的烧杯中隔水加热 ②把天竺葵放在光下照射
③用黑纸片把天竺葵叶片遮盖一部分 ④把天竺葵放在黑暗处一昼夜
⑤把部分遮光的叶片摘下,去掉黑纸片 ⑥用清水漂洗叶片后滴加碘液.
-7____-5 1.5____5 20____-2.4 -3.1____3.1