Take scientists involved in the research on "Two missiles and one satellite" in China over fifty years ago. At that time, we did get some help from the Soviet Union, but most of the research was conducted by Chinese scientists on their own. Out of patriotism and amid a severe famine, these scientists did almost all the calculations by hand, worked on research day and night, and finished one experiment after another. They had no one but themselves to turn to. Their diligence and devotion finally paid off. Without the spirit of self-reliance, nothing could have been possible in such a short time.
This paragraph is unified.
A、正确
B、错误