– You ought to see a doctor about that cough.
-- I guess I should. I _____ it off for days.
| A．put | B．was putting | C．have been putting | D．am putting |
The disappearance of dinosaurs made _______ the evolution and dominance of mammals on the earth.
| A．it was possible | B．it possible | C．possible to be | D．possible |
I felt most angry about the way ______ I was treated when I was shopping.
| A．when | B．that | C．which | D．where |
Regarding China-US differences on human rights issues, Hong said the two sides can enhance mutual understanding through dialogue ______ on equality and mutual respect.
| A．based | B．to base | C．basing | D．base |
When we start gazing into the night sky with a telescope, soon we’ll be astonished by the realization _______ we and our world are part of this giant system.
| A．which | B．whether | C．that | D．as |
Karaoke, which was invented by the Japanese, ______ both wonders and problems.
| A．has been produced | B．was produced | C．produced | D．has produced |