服装店销售某款服装，一件服装的标价为300元，若按标价的八折销售，仍可获利60元，则这款服装每件的进价为____ 元．

①函数y=4cos2x，x∈﹣10π，10π不是周期函数；

②已知定义域为R的奇函数f（x），满足f（x+3）=f（x），当x∈（0， $\frac{3}{2}$ ）时，f（x）=sinπx，则函数f（x）在区间0，6上的零点个数是9；

③为了得到函数y=﹣cos2x的图象，可以将函数y=sin（2x﹣ $\frac{\pi }{6}$ ）的图象向左平移 $\frac{\pi }{6}$ ；

④已知函数f（x）=x﹣sinx，若x₁，x₂∈﹣ $\frac{\pi }{2}$ ， $\frac{\pi }{2}$ 且f（x₁）+f（x₂）＞0，则x₁+x₂＞0；

⑤设曲线f（x）=acosx+bsinx的一条对称轴为x= $\frac{\pi }{5}$ ，则点（ $\frac{2\pi }{5}$ ，0）为曲线y=f（ $\frac{\pi }{10}$ ﹣x）的一个对称中心．

其中正确命题的序号是____．

根据对话内容，从下列选项中选出能填入空白处的最佳选项，其中有两个为多余选项。

— Hello. Gerry speaking.

— Hello, Gerry. It's me John here. ____ .

— Well, I'm terribly sorry, but I'm not feeling very well.

— Is that all?____

— No, I'm sorry. I was sick all night. I think it must be the fish I ate last night.

— Well, I think you should have at least phoned Kate and told her you weren't coming to the meeting.

— ____ I'm sorry about that. Anyway, I think I'll be able to get in to work tomorrow.

— ____ 

— I won't. Thanks for calling.

— ____.

A. Why didn't you phone?                 

B. OK. Take care and don't eat any more fish.

C. Why weren't you here at the meeting?      

D. That's all right.

E. We thought you might have had an accident or forgotten the day or something.

F. I'll be glad to see you again.          

G. Yes, I suppose I should have done so.

下列图示实验操作正确的是（　　）