桥式接线有内桥和外桥两种形式。
参考答案：错
We narrowly escaped _____in the forest of South America 15 years ago.
A．killing
B．to be killed
C．to have been killed
D．being killed
首次提出社会主义社会基本矛盾的是
A．列宁
B．斯大林
C．毛 * *
D．刘 * *
