243.

W: David, we shouldn't sit here doing nothing.

M: Why not? It's Saturday afternoon, isn't it?

W: Yes, but there's so much to do around the house.

M: It can wait.

W: We ought to finish washing down the kitchen walls and cupboards.

M: We can do that tomorrow. We don't have to do it today.

W: All right. That's a good idea.

M: Talking about washing down the kitchen-where's Bob?

W: He's having lunch with Georgia.

M: What! Again?

W: He should be back soon.

M: He shouldn't spend so much time with that girl.

W: You must be patient, David. Nineteen's a very difficult age, you know?

M: Yes, I know. But he ought to be studying more.

答案解析：

(1) 正确答案为B。根据It's Saturday afternoon, isn't it?现在是周六下午，不是吗？可知，对话发生的时间为下午，因此B项正确。

(2) 正确答案为C。根据女子说We ought to finish washing down the kitchen walls and cupboards.我们要清洗厨房的墙壁和壁橱。和男子说We can do that tomorrow. We don't have to do it today.我们可以明天再做。我们不必非得今天做。可知，二人打算明天清楚厨房，因此C项。

(3) 正确答案为A。根据He's having lunch with Georgia.他在和乔治娅吃午餐。可知，鲍勃现在在餐厅，因此A项正确。