现在进行时
1.概念：表示现阶段或说话时正在进行的动作及行为。
2.时间状语：Now, at this time, days, etc. look. listen
3.基本结构：主语+be +doing +其他
4.否定形式：主语+be +not +doing+其他
5.一般疑问句：把be动词放于句首。
6.例句： How are you feeling today?
He is doing well in his lessons.
