...referring to logical AND, connects two words. And can be...
C、使用“OR”或“or”连接两个关键词都行,不区分大小写 To connect two keywords, either capitalized “OR” or “or” can be used. D、"OR"表示逻辑与的概念,连接的两个关键词出现一个即可,"OR"本身可省略不写 “OR", referring to logical AND, connects two words. And can be omitted. It only...