and,or用法与区别
问题描述：
and,or用法与区别
答
1.是否定句之后通常用 or代替 and.如：He spoke loudly and clearly.他说话声间宏这且清晰.He didn’t speak loudly or clearly.他说话声音不大且不清晰.2.祈使句＋and =if,而祈使句＋or = unless.如：Work hard,and...