Some people          feel sick when they read a book in a car or on a boat．

 ---There is somebody knocking at the door. Who________ it be?---I’m not sure. It ________ be a postman.

 Personally, the job as a teacher _____ be challenging, for I sometimes _____ deal with some smarter but less diligent students. 

If people eat natural plant poisons by mistake, they _______ go to hospital without delay.

No one likes him ____.