高压杆两杆之间的间距一般不超过（）m。
A、30~50
B、50~100
C、80~100
D、30~100
参考答案：D
The DiaoYu Island have been part of China’s territory since ancient times, __________as important fishing grounds of Taiwan.
A．served
B．serving
C．to serve
D．having served
人民警察义务，是指人民警察在行使权力、履行职责过程中必须作出一定行为的约束。 ( )
