氧气瓶中的氧气不允许全部用完，当压力剩至0.2兆帕时，就要停止使用。
参考答案：对
-Is your father a Party member ?
- Yes, he the Party three years ago. He a Party member for three years .
A．has joined; has been
B．joined; has been
C．joined ; was
D．was joined; is
中 * * 党第二代领导集体的核心是 [ ]
A．毛 * *
B．邓 * *
C．江 * *
D．胡 * *
