下列说法不正确的是（）：A、用参数w（z）和R（z）可以表征高斯光束 B、用q参数

—The manager has come back from his business trip. He is asking you for the report.

—Oh，my god ! I haven’t finished it yet. But he____ back at the company tomorrow.

A．was expected

B．will expect

C．expected

D．will be expected

若a²+b²=35，a²b-ab²=-6，求（a²-b²）+（3a²b-a²b）-2（ab²-b²）的值．

补全对话。

A: Good morning! Can I (1)       you?

B: Yes, please. I'm (2)     for a pair of jeans.

A: Yes, just a (3)      . There (4)       some jeans and jackets here. (5)      a look.

B: How much are the jeans?

A: ￥250.

B: Oh, that's too (6)      . Do you have a (7)      one?

A: Yes, There's a discount on last year's (8)     . They're only ￥150. What (9)       do you

want?

B: Size eight. Could I try them on?

A: Yes, of course.

B: Oh, they (10)      me very well. I'll buy them.

RR表示（）。

A.比值比

B.相对危险度

C.特异危险度

D.人群特异危险度

E.特异危险度百分比

每一个心动周期中动脉血压下降的最低值称为（）

A.收缩压

B.舒张压

C.脉压

D.平均动脉压

E.体循环充盈压