—____, Tom. Is this your pen?—No, it isn’t. I think it’s ____.
Why didn’t you go to the party last night? – I __________.
I find it difficult _______ up Mount Tai.
When people want to relax themselves, they prefer _________ TV rather than _______ newspapers.
Albert Einstein was _______a great scientist.
We were all _______with the _______trip to Dalian.