It won’t be quite a long time ________ your son is back, so don’t be worried.
| A．that | B．since | C．before | D．until |
Many countries are now setting up national parks________animals and plants can be protected.
| A．when | B．which | C．whose | D．where |
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 |