被俄罗斯人称为“母亲河”的是( )
A:伏尔加河
B:叶尼塞河
C:多瑙河
D:乌拉尔河
A: Hi, Jenny!____ my birthday party on Saturday afternoon?
B: Sure,____.
A:____you, Linda?
C: I'm sorry I can't. I ____ study for a test on weekends.
A: That's too bad. Maybe next time.
C: Sure. Thanks for your ____.