【B15】A．byB．forC．uponD．from

【C4】______A．calling offB．calling forC．calling uponD．calling up

【C20】A．onB．forC．uponD．at

The second engineer seemed to know what the sign ______.A.stand byB.stand forC.stood byD.s

【C8】A．byB．forC．withD．without

【C3】A．byB．withinC．uponD．for

Between 2001—201 1, the number of overseas visitors expanded ______ 55%.A．byB．forC．toD．in