What color is the sweater？

如图所示，一带负电的油滴，从坐标原点O以速率v₀射入水平的匀强电场，v₀的方向与电场方向成θ角，已知油滴质量为m，测得它在电场中运动到最高点P时的速率恰为v₀，设P点的坐标为(x_p，y_p)，则应有（   ）

补全对话

从方框中选择最佳选项完成对话，有两项多余

a. Yes!

b. The keys? They're on the table.

c. No, they aren't.

d. How about my books?

e. It's under the desk.

f. Where are they?

g. Thank you very much.

A: Hi, Susan! My keys（钥匙） are lost（丢失）. ____

B: Are they on the table?

A:____

B: En. . . Are they in your bag?

A: But where is my bag?

B:____

A:____They are here. But there aren't any books in my bag.

B: Ha- ha. Are they lost, too?

A: Oh, no.

B: Look! They are on the shelf (架子).

A:____

B: Not at all.

（Ⅰ）问电视台每周应播放两部影片集各多少集，才能使收视观众最多；

（Ⅱ）在获得最多收视观众的情况下，影片集甲、乙每集可分别给广告公司带来a和b（万元）的效益，若广告公司本周共获得3万元的效益，记S= $\frac{16}{a}$ + $\frac{10}{b}$ 为效益调和指数（单位：万元），求效益调和指数的最小值．