Experts found a large quantity of wall paintings, some of them_____ the Han Dynasty.
| A．dating back to | B．dated from | C．dated back to | D．dates from |
Everyone has a form in his hand, but no one knows which office ___.
| A．to have it sent | B．to send it | C．to send it to | D．to be sent to |
He did poorly in the exams, ___ how hard he tried for them.
| A．to consider | B．considering | C．to regard | D．regarding |
There are many valuable services which the public are willing to pay ___, but which __ not bring a return in money to the community.
| A．to; do | B．不填；does | C．for; does | D．for; do |
. In no country other than Britain, it has been said, ____ experience for seasons in the course of a single day.
| A．you can | B．people can | C．can one | D．can it |
_ Mr. Morgan appears extremely cheerful in public, he is in fact leading a very unhappy life.
| A．As | B．Since | C．While | D．When |