According to the air traffic rules, youswitch off your mobile phone before bearding.
| A． | may | B． | can | C． | would | D． | should |
It was only when I reread his poems recently______ I began to appreciate their beauty.
| A．until | B．that | C．then | D．so |
Last term our maths teacher set so difficult an examination problem ______none of us worked out.
| A．that | B．as | C．so that | D．which |
His grandfather was among the first to settle in_______ is now a famous holiday center.
| A．which | B．what | C．where | D．that |
E-mail, as well as telephones, an important part in daily communication.
| A．is playing | B．have played | C．was playing | D．play |
Though ________ money, his parents managed to send him to university.
| A．lacked | B．lacking of | C．lacking | D．lacked in |