A．开关失灵
B．灯泡灯丝断了
C．家用电器的总功率太大
D．将开关中的两个接头相碰
答案：C
下列与强直性脊柱炎密切相关的是()
A．HLA-DR9
B．HLA-DR4
C．HLA-B27
D．HLA-DR2
E．HLA-DR5
Chemical processes _______in the treatment of materials for clothes _______the environment badly in some countries nowadays．
A．involve；damaging
B．involved；damaged
C．involving；damage
D．involved；damage
