"Be" 作为句首时，通常需要使用动词原形。She is a doctor.（她…

放在句首是祈使句give基本的词义是给，give作及物动词时可接名词或…

Use both formal and informal channels (to make ...)(you…

Use both formal and informal channels (to make ...)(you…

动词的四种形式doing,done,do,todo都可以置于句首。一般来说，动词…