【单选题】一般模具型腔表面粗糙度值要比塑件表面的低( )。
【多选题】下列哪两种抗菌药药物合用可获得协同作用______
【单选题】Your sister used to visit you quite often, ______?
【单选题】—Did your father _____ catch a cold? —No, he didn't. But he _____ the weather here. [ ]
【单选题】I a lot but I don't play very often now. [ ]
B.
was used to play tennis
C.
am used to play tennis
【多选题】根据支付结算法律制度规定,下列关于2010版票据的说法中,正确的有( )。