矿粒按密度分层的基本条件是（）
A、床层松散
B、给足频率
C、给足风量
D、给足水量
E、脉动水流
F、振幅合适
参考答案：A, B, C, D, E
新生儿败血症国内最常见的病原菌是（），其次是（）。
情景交际。
A.
Jim: ①._____ me, Jenny. Is this your ②._____ ?
Jenny: Yes, ③.____ you. It's my ruler.
Tim: And is this your ④._____ ?
Jenny: No, ⑤._____ isn't.I think it's ⑥._____ dictionary.
B.
A: Hello, Sonia. Nice to meet you.
B: Hi, Mike. ⑦._____
A: How are you?
B: ⑧._____ And you?
A: I'm OK.⑨._____
B: Yes, it is. It's my book.⑩._____
A : That's all right.
