Oh, dear! There isn’t enough _____ for us in the lift. Let’s wait for the next.

 I listened to Professor Chen-Ning Franklin Yang’s lecture about his study and physics, but I failed to get its key ______ .

---Could you please help me check what's wrong? ---Sorry, I don't have much _______of the computer.

—Hello, Betty. Is your mother a teacher?  —No, she is a doctor in a _____.

 — I like reading very much.— Me too. I especially like the__________ written by J. K. Rowling.