振动放矿时，被放矿石或岩石在（）和振动场共同作用下，成平稳连续的矿岩流放出。
参考答案：重力场
It is suggested that you live ______ good and honorable life. Then when you get older and think back, you’ll get to enjoy it ______ second time.
A．a; the
B．a; /
C．a; a
D．/; the
