Gou-de-le, which is one of the largest supermarket Meitans, _____ some of its stores open 24 hours on Mondays through Saturdays.

A．keep

B．have kept

C．had kept

D．keeps

下列各组物质互为同分异构体的是                                                         （   ）

A．苯甲醇和甲基苯苯酚

B．乙醇和乙醚

C．丁二烯和2—丁烯

D．乙醇和乙二醇