烟气中氧含量控制在（）。
A.2～5%
B.0.2～1%
C.2～3%
参考答案：C
我国流行的常见菌群是
A．宋内志贺菌B．痢疾志贺菌C．福氏志贺菌D．鲍氏志贺菌E．痢疾志贺菌和鲍氏志贺菌
读一读，写出问题。
A: 1._____________ Lucy?
B: She is in the classroom.
A: 2.______________________ ?
B: She is cleaning the room.
A: 3.________________________ ?
B: She usually comes to school at8:00.
A: 4._________________________ ?
B: Oh, I'm reading a book.
