题目
为了探究水电解的微观过程,某同学做了一些下图所示的分子、原子的模型, 若用“”表示氢原子,用“”表示氧原子,其中能保持氢气的化学性质的粒子是( ) A. B. C. D. 答案:A
读句子,选择恰当的图片并将其字母填入题前括号内。
( ) 1. A: What's this? B: It's a lion. It's fat and short.
( ) 2. Look at the bag. It's big.
( ) 3. A: What are they? B: They are pandas. They are fat.
( ) 4. A: What's this? B: It's an elephant. It's big.