We were told not to touch the equipment in the laboratory unless ________.
| A．allowed to do | B．allowing to do |
| C．allowed to | D．allowing to |
Singing with Sun Yang，the swimming champion，face to face is an unforgettable moment，________ the little girl always treasures.
| A．one | B．this | C．that | D．it |
Although his excuse was as good as ________ other，I don't believe that was a fact.
| A．one | B．each | C．every | D．any |
—What do you think about smoking?
—Well，just as someone puts ________，smoking kills.
| A．this | B．it | C．that | D．one |
Mr Blark，________ who we all admire，is a kind but strict teacher.
| A．the one | B．it | C．one | D．as |
Mary's parents admitted that she was always contrary to a wish of ________.
| A．them | B．theirs |
| C．their | D．themselves |