问题
After visiting the science museum, the students don’t doubt _________
A:how far is Mars away from the sun
B:what is the transport like on Mars
C:of the distance from the sun to Mars
D:the life on Mars will be different from the life on the Earth;
B:what is the transport like on Mars
C:of the distance from the sun to Mars
D:the life on Mars will be different from the life on the Earth;
正确答案是：
