—What does PM 2.5 mean?
—It's a professional ________ indicating the condition of air pollution.
| A．term | B．item | C．number | D．mark |
．________ bricks，workers press clay into blocks and bake them to the requisite hardness in a kiln.
| A．Made | B．To make |
| C．Being made | D．To be made |
New ideas sometimes have to wait for years before ________.
| A．being fully accepted | B．fully accepted |
| C．fully accepting | D．fully being accepting |
________ the past，our life is much better.
| A．Comparing with | B．Be compared |
| C．To compare with | D．Compared with |
________ for several weeks，the city needed food.
| A．As having flooded | B．Being flooded |
| C．Having been flooded | D．To flood |
I went to see him，________ him out.
| A．finding | B．find |
| C．only to find | D．to finding |