Our teacher is always busy preparing lessons until 11 o’clock at night, _____we students have gone to sleep.
| A．that time | B．by which time | C．by that time | D．which time |
Cheer up! Everyone may have periods in their liveseverything seems tough.
| A．which | B．where | C．when | D．that |
______ piano is her main focus, she's also great at guitar.
| A．Since | B．Once | C．Unless | D．While |
With the nuclear crisis worsening in Iran, the world's attention is fixed again onis called the Middle East.
| A．which | B．that | C．what | D．it |
-- I can’t believe that Jeff _______ have quarreled and fought with his boss.
-- Well, if one _______ ask for trouble, it just can’t be helped.
| A．would; will | B．must; may | C．should; must | D．need; dare |
In 1778, Bank was elected _________ president of the Royal Society, ________ position he held for 43 years.
| A．the; the | B．不填; a | C．a; a | D．不填; the |