《低压配电设计规范》规定，电缆的长度，宜在（）留有一定余量
A.进户处
B.接头
C.电缆头
D.地沟及隧道中
参考答案：A, B, C, D
The young manager is well known for his problem-solving skills, ________ is important for a successful leader.
A．it
B．that
C．what
D．which
绘图题：
