The book was written in 1946,the education system has witnessed great changes.
| A． | when | B． | during which | C． | since then | D． | since when |
In my brother's absence, I would like to thank all concerned on his ________.
| A．behalf | B．part | C．business | D．interest |
—What does PM 2.5 mean?
—It's a professional ________ indicating the condition of air pollution.
| A．term | B．item | C．number | D．mark |
It is no ________ pretending you did not know because everyone saw the whole accident.
| A．use | B．help | C．time | D．joke |
—He has a lot of friends who have a lot in ________ common with himself.
—Indeed.Birds of ________ feather flock together.
| A．the; / | B．the; a | C．/; a | D．a; the |
Finding information in today's world is easy.The ________ is how you can tell if the information you get is useful or not.
| A．knowledge | B．ability |
| C．competition | D．challenge |