为确保人身安全，（）处所应双接地。
（A）隔离开关
（B）避雷器
（C）吸流变压器
（D）站台上及人员活动频繁处的支柱
参考答案：D
On the international market, the price of petroleum has been falling down, which is now _____ it used to be.
A．as one third as
B．one third as much as
C．one third more than
D．as one third much as
促使孙中山在思想上由学习西方到联合苏俄的主要因素是（）
A.帝国主义对中国革命一再破坏
B.由于苏俄方面的积极争取
C.受中共的直接帮助
D.由于陈炯明叛变的极大刺激
