【单选题】X元素的原子最外层有2个电子。Y元素的原子最外层有7个电子,X和Y形成的化合物分子式为( )
【单选题】--- Hello! My name ’ s Mary. --- ____________.
【简答题】补全对话。 Mary: Hello, this is Mary. Mr White: Hello, this is Mr White, Peter's father. Mary: Hello, may I speak to Peter? Mr White: Sorry, (1)________________. Mary: Could you tell me when he'll come bac...
【单选题】他病了,大家都( )他今天不会来上课,但他还是来了。
【单选题】【英语 [ 单选题 ] 】 --- Hello, 8254169, who’s that? --- ______________. A. I’m Mary. B. That’s Mary. C. This is Mary. D. I don’t know you.
【单选题】X元素原子的最外层有6个电子,Y元素的原子最外层有2个电子,X、Y元素化合形成的离子化合物的化学式为( )。
【单选题】SpeakerA:Hello, Mary. Will you be free this evening? SpeakerB: