Collecting stamps as a hobby ________increasingly popular during the past fifty years。
| A．becomes | B．became | C．has become | D．had become |
Teachers have to constantly update their knowledge in order to maintain their professional ___.
| A．consequence | B．independence | C．competence | D．intelligence |
It was never clearthe man hadn't reported the accident sooner.
| A． | that | B． | how | C． | when | D． | why |
In that school, English is compulsory for all students, but French and Russian are___
| A．special | B．regional | C．optional | D．original |
Between the two parts of the concert is an interval, ___the audience can buy ice-cream.
| A．when | B．where | C．that | D．which |
——Tommy is plannning to buy a car.
——I know. By next month, he ___enough for a used one.
| A．saves | B．saved | C．will save | D．will have saved |