He couldn't _________an answer when I asked him why he was late.
— Can you tell me ________?— His home is quite far from the office, I think.
We will go to Tian’anmen Square to watch the raising of national flag if it ________ tomorrow.
— How often do I need to feed the dog?— It ________ food every day, or it will be hungry.
My friend and I are interested in drawing, but ________ of us is good at it.
— Is Jack in the next room?— Well, it’s hard to say. But I heard him ________ loudly when I passed by just now.