在运行区域设备及设施拆除作业,弃置的动力电缆头、控制电缆头,除有短路接地外,应一律视为()。
A.不带电
B.有电
C.有用
D.无用
参考答案:B
若曲线y=ex+a与直线y=x相切,则a的值为______.
30. It is said that Columbus Day is ______ the arrival of Christopher Columbus in the New World in the USA.
A. in honor of B. for the honor of C. in favor of D. in place of