上、下水室腐蚀不严重,仅有少数()或()时,可用()修理。
参考答案:小孔;腐蚀斑点;镀锡法
The author believes that it is the test system,________ the teachers, that is to blame for the heavy burden of middle school students.
A.other than
B.or rather
C.rather than
D.more than
计算机信息系统的物理安全所保护的对象包括()。
A.防火、防盗
B.防雷保护
C.计算机硬件安全
D.网络设备的安全