不定项选择题 There are three countries that have sent spacecraft to the moon, the U.S., Russia and the third which soft landed a rover there back in 2013 in China. But China hopes to become the first country to explore the dark side of the moon or the far side. The part that never faces Earth. China has a mission plan this year. Though a launch date hasn't been announced yet. One problem with exploring the dark side of the moon is that there's no easy way to communicate with whatever kind of vehicle people put there. The moon itself would block any signals coming from Earth. So, to address that, China launched a satellite earlier this year that will hang out in the moon's orbit acting like a relay station between the Earth and the new rover that China's planning to send to the moon later this year. The country is a relatively late entry into space exploration. China didn't sent its first satellite into orbit until 1970. But over recent decades, it's funneled billions of dollars into space research. It's hoping to ultimately set up a base on the moon that's run by robots. And it's also setting its sights on Mars. China is hoping to send some spacecraft there starting in 2020.
Why it's not easy to explore the dark side of the moon? ( )

A The dark side is the farthest part from the Earth.

B The moon will block any signals coming from Earth.

C The dark side never faces Earth.

D Have to launch a satellite that will hang out in the moon's orbit.