to be doing 这个结构可以做主语吗?比如 To be walking in a sandstorm is fr

to be doing 这个结构可以做主语吗?比如 To be walking in a sandstorm is fr be to do 和 be doing 做主语 请问seem作系动词时,主语+seem+to be+表语,这个句子结构里的to be 都可以省略吗? be used to doing的主语可为物吗 be used to doing.be 可以用过去式吗? to be doing 结构能在句子中做结果状语吗? be in the movie 是看电影还是演电影 有be strict to 这个结构吗? be worth to be done 有这个结构吗 There is going to be a football match tomorrow,这里的be 可以换做hav to be doing为什么不能非谓语动词作主语 23."Life is like walking in the snow",Granny used to say,"be be successful in +doing 还是 to do?