What is the most important factor for a rocket to escape from the Earth? As there is always the Earth’s gravitational(地心引力的)pul

admin2009-06-15 100

问题 What is the most important factor for a rocket to escape from the Earth?
As there is always the Earth’s gravitational(地心引力的)pull, people ______.

选项 A、accept it without questioning it
B、never notice its presence
C、hardly think about how to use it
D、often try to escape from it