氧气瓶可以使用到没有剩余气体，然后送专业厂家灌气。
参考答案：错
— What’s the matter with Della?
— Well, her parents wouldn’t allow her to go to the party, but she still ________.
A．hopes to
B．hopes so
C．hopes not
D．hopes for
我国城市燃气管道按输气压力来分，次高压A燃气管道压力为（）。
A.0.4MPa
B.0.8MPa
C.1.6MPa
D.2.5MPa
