只有当被担保合同不履行或不完全履行时，担保合同才发生法律效力。
参考答案：对
应急照明灯和疏散指示标志连续供电时间不应少于( )高度超过100m的高层建筑连续供电时间不应少于( )。
A．20min,30min
B．10min,30min
C．20min,15mm
D．30min,50min
It was not _____ she took off her glasses _____ I realized she was a famous film star.[ ]
A. when, that
B. until, that
C. until, then
D. when, then
