_______ that we can't get the necessary equipment, we will have to give up the
experiment.
| A．To assume | B．Assume | C．Assumed | D．Assuming |
The person____drugs had much difficulty in getting rid of the_____.
| A．addicted; addict | B．addicted to; addiction |
| C．addictive to; addict | D．addictive; addiction |
Years later, I began ______ what he told me right.
| A．knowing | B．to know |
| C．recognize | D．to recognize |
It’s no use ______ with him ______ this matter.
| A．arguing; for | B．arguing; over |
| C．to argue; over | D．to argue; about |
______ the distance was too long and the time was short, we decided to fly there instead.
| A．Discovering | B．To discover |
| C．To have discovered | D．Discovered |
—What’s the matter with you, Tom?
—______ the ladder, one of arms has been broken.
| A．Climbing | B．While climbing |
| C．To climb | D．While I was climbing |