The retired professor, _____ in his new book in the past three years, hasn’t realized the decline in his health．
| A．involved | B．being involved |
| C．having involved | D．to be involved |
_________ mother is a worker.
| A．Mary and Mike's | B．Mary's and Mike's | C．Mary's and Mike | D．Mary and Mike |
At that time, he was studying in_______ university. And it was a famous one.
| A．/ | B．the | C．a , | D．an |
Our teacher told us that _______ moon moves around ______ earth, and
________ earth circles________ sun.
| A．a, a, a, a | B．an, an, an, an | C．the, the, the, the | D．/, /, /, / |
There is egg on the table, egg is for you.
| A．a, A | B．an, An | C．an, The | D．the, An |
Let's look at the bag. Can you see _____“s”on the corner of_____ bag?
| A．a, a | B．a, the | C．an, a | D．an, the |