_____ in the library regulations that any book borrowed be returned by due time, or the borrower will be fined．
| A．What is required | B．It is required |
| C．As is required | D．Which is required |
____ with the size of the whole earth, the highest mountain doesn’t seem high at all.
| A．To compare | B．while comparing | C．It comparing | D．when compared |
I ______ my university professor in the supermarket near my house, which was out of my expectation.
| A．came out | B．came across | C．came about | D．came along |
I was not _______her presence till she spoke to me.
| A．aware | B．aware about | C．aware of | D．aware to |
There is no need ______ because Mr. Smith is still sleeping.
| A．to hurry | B．hurrying | C．hurry | D．hurried |
When ____about his family, he is always refusing to answer.
| A．asked | B．asking | C．being asked | D．mentioned |