27. The Grand Theatre in Shanghai is open to visitors during the daytime ______ there is a performance going on.
| A．when | B．except for |
| C．except when | D．Except |
—Have you ever visited the Opera House?
—Yes．When I was in Sydney, I___it twice．
| A．had visited | B．visited | C．have visited | D．would visit |
In recent years,___global warming is becoming___concern for people all over the world．
| A．the; the | B．不填；不填 | C．不填；a | D．the; 不填 |
What I need is nothing but an interesting book,___ that can kill the time tonight
| A．it | B．that | C．one | D．the one |
—How did you find the last night’s performance?
—Wonderful! I’ve never seenone．
| A．the best | B．a better | C．so good | D．so better |
Elizabeth took up writing while she was at college and regularlythe college magazine, which benefited her later career a lot．
| A．waited for | B．appealed to | C．contributed to | D．came for |