— What's the matter with the man hanging his head there?— Well, if you _____ know, he was caught stealing my bike. 

 She often shares her deepest thoughts and fears with friends through QQ, as if they ________ chatting in her living room.

After her son’s death, the old lady __________ sit at the window, deep in thought.

“I’ve told him about it.” “But I’d rather you ______.”

You _____ pay too much attention to your reading skill, as it is so important.