—What does PM 2.5 mean?
—It's a professional ________ indicating the condition of air pollution.
| A．term | B．item | C．number | D．mark |
As everybody knows, Hong Kong used to be _____ part of _____ British Empire．
| A．不填; a | B．a; the | C．不填; the | D．the; 不填 |
The manager decided to give the job to _____he believed had a strong sense of duty .
| A．who | B．whom | C．whomever | D．whoever |
This is the last chance to go abroad for further education ; don’t _____.
| A．take it away | B．give it away | C．put it away | D．throw it away |
_________ happened to be no one in the building when the fire broke out.
| A．It | B．There | C．This | D．That |
The police got to ___ was once an old school ___the peasants used as a store .
| A．what , that | B．where , which | C．where , that | D．which , where |