From the dates__________on the gold coin, we decided that it was made five hundred years ago.
| A．marking | B．marked |
| C．to be marked | D．having been marked |
Can _____ be in the desk _____ you have put my letter？
| A．it；which | B．I；Where | C．you；in which | D．it；that |
Time should be made good use of ____ our lessons well.
| A．learning | B．learned | C．to learn | D．having learned |
---What do you think made the woman so upset？
--- _____ weight.
| A．As she put on | B．Put on |
| C．Putting on | D．Because of putting on |
The research is so designed that once ____ nothing can be done to change it.
| A．begins | B．having begun | C．beginning | D．begun |
______ in thought, he almost ran into the car in front of him.
| A．Losing | B．Having lost | C．Lost | D．To lose |