题目

农业上用射线或药物处理农作物种子，获得新品种的原理是射线或药物     A．直接改变了农作物的某些性状     B．改变了农作物种子中的营养成分     C．淘汰了农作物的某些不良性状     D．使种子里的遗传物质发生了改变 答案：D小题1:.. You can find out the reason for this f__________ (失败).小题2:.. No one can a__________ (取得成就) anything without effort.小题3:.. That rich man has a large staff of s__________ (仆人).小题4:.. He made a v__________ (航海) to Australia last year.小题5:.. O__________ (氧) is a gas without color, taste or smell, present in the air and necessary for us all.小题6:.. The d__________ (密度) of the fog made it difficult to see where we were going.小题7:.. People of different r__________ (种族) may have different colors of skin, hair and eyes.小题8:. The r__________ (逃跑的) slave was caught by his owner and was almost beaten to death.小题9:.. “You never ask my opinion about anything,” Rod c__________ (抱怨).小题10:.. S__________ (有经验的) teachers have the experience needed to make their lessons interesting.