按照下面的规律穿珠子，第29颗珠子是白色还是黑色?

Mr. and Mrs. Button's house is t____ old. They want to buy a new one. Now they are t____ about a new house.

Mr. Button: How about this one, darling?

Mrs. Button: It's OK. How many floors are t____?

Mr. Button: Three floors. On the f____ floor, there is a big living room. We even can have a party here.

Mrs.: Oh, look. The k____ is so big. I can cook a big meal for you and the children every day. I like it. And it f____ south. It's so bright.

Mr. Button: Go upstairs. Oh, there are two b____ here and one s____. We can read books and surf the internet here. I like it.

Mrs. Button: How about the third floor?

Mr. Button: There is no third floor. It's o____ two floors. Do you like this h____?

Mrs. Button: Yes, I love it.

漫画《“愚公移山”新传》的寓意是（  ）

火星探测项目是我国继载人航天工程、嫦娥工程之后又一个重大太空探索项目，2018年左右我国将进行第一次火星探测．已知地球公转周期为T，到太阳的距离为R₁，运行速率为v₁，火星到太阳的距离为R₂，运行速率为v₂，太阳质量为M，引力常量为G．一个质量为m的探测器被发射到一围绕太阳的椭圆轨道上，以地球轨道上的A点为近日点，以火星轨道上的B点为远日点，如图所示．不计火星、地球对探测器的影响，则（   ）