GWl6．17型隔离开关静触杆的直径为（）mm
A.55
B.50
C.454
D.40
参考答案：D
–I feel a little nervous ____ the exam .
--______. All of the students may feel nervous.
A．take, Don’t worry.
B．taking, Take it easy
C．to take, Don’t be worried
D．took, Come on.
热水锅炉运行时的注意事项有哪些？
