She is too thin. She _______ gain some weight but she ______ too little. 

Tony ____ the invitation, otherwise he would have attended your birthday party. 

—I didn’t attend the lecture yesterday.—I ______, either, if my mother hadn’t reminded me. 

As if he ______ my mind，he stood up and offered me his seat when I got on the crowded bus.

. The movie was totally a waste of time. I ______ just as well have stayed at home.