防止病邪侵害属于
A.因时制宜B.未病先防C.因人制宜D.因地制宜
参考答案:B
He had a wonderful childhood, _____ with his mother to all corners of the world. [ ]
A. travel
B. to travel
C. traveled
D. traveling
字长是计算机的一个主要性能指标,字长越短,计算机的运算速度和效率就越高。( )