题目

If you are travelling ____________ customs are really foreign to you, please do as the Romans do. A . where B . when C . that D . which 答案：A我国著名遗传育种家袁隆平培育的新型生物是（ ）A．杂交水稻B．杂交小麦C．克隆羊D．转基因鱼