Only when he reached the tea-house ______it was the same place he’d been in last year.
| A．he realized | B．he did realize |
| C．realized he | D．did he realize |
In front of our school ______, where a lot of people play or take exercise at any time.
| A．does a park lie | B．is a park lie |
| C．a park lies | D．lies a park |
His study in Peking University lasted four years, ______ he founded his own company in Hong Kong.
| A．after which | B．after when |
| C．after that | D．after it |
I just don’t understand _______ that prevents so many Americans from being as happy as one might expect.
| A．why it does | B．what it does |
| C．what it is | D．why it is |
—What do you think of _____gifted chemist from London?
— Well, sometimes his behavior is beyond ______comprehension.
| A．a; the | B．the; / |
| C．the; the | D．a; / |
— Did you remember to give Jack the book?
—Yes, I gave it to him ______ I saw him.
| A．while | B．immediately |
| C．once | D．suddenly |