He was unable to make such progress, ____.
| A．hard as he tried | B．as hard he tried |
| C．hard he has tried | D．tried hard as he |
.
In his opinion, man should try to make ________ most of the natural resources in ________Atlantic Ocean.
| A．/; the | B．/; / | C．the; the | D．the; / |
.
The man to whom we handed the forms pointed out that they had not been ________ filled in.
| A．slightly | B．properly | C．regularly | D．eventually |
.
Playing with a cell phone, he suddenly ________ the teacher staring at him.
| A．knew of | B．became aware of |
| C．reflected | D．aware for |
.
She seemed ________ the book before, but she said she had never.
| A．to read | B．to have read | C．to be reading | D．reading |
.
________ on the subject for half an hour, Liu Ying suddenly stopped.
| A．To be worked | B．To work |
| C．Having worked | D．Having been worked |