— Did you know any Chinese before you arrived in Beijing?
— Never ________ it, actually.
| A．had I learned | B．have I learned | C．I have learned | D．I had learned |
It was the largest experiment we had ever had; it _____ six hours.
| A．ended | B．finished | C．prolonged | D．lasted |
I have been looking for this book for months, and _____ I have found it.
| A．at least | B．in no time | C．at last | D．at present |
He offered to _____ her a hand as the suitcase was too heavy for her to carry.
| A．lend | B．help | C．show | D．loan |
I'm sorry but what he thinks is not of the _____ importance to me.
| A．merest | B．lowest | C．last | D．least |
Animals should not be locked in cages; they should be in their normal _____.
| A．environment | B．position | C．residence | D．dwelling |