Mary dropped in ____ Mr Smith, but he wasn' t at home, so she went to drop in ____ Mr Smith's office.
| A．on, on | B．at, at | C．on. at | D．at. on |
Whenever asked to help me with my lessons, he always refuses, ______ he is too busy.
| A．to say | B．saying | C．says | D．having said |
______ its size with that of the whole earth, we find the highest mountain does not seem high at all.
| A．When compared | B．Compared to |
| C．To be compared | D．Comparing |
“How can we go outing in this kind of weather!”! Bob said,__________ out of the window.
| A．looking | B．looked | C．to look | D．having looked |
All the preparations for the work_______, we’re ready to start.
| A．are completed | B．have been completed |
| C．completed | D．had been completed |
With so much work his head all day long，he feels rather stressed in his daily life．
| A．filled | B．to fill | C．filling | D．being filled |