1．(2012·泉州调研)—Mum, I have finished all my homework. Could I go downstairs to play with other children?
—Certainly, but don't remain out ________ nine o'clock.
A．through B．over
C．before D．beyond
解析：考查介词。根据“不要在外面玩到超过九点钟”可知beyond“晚于，迟于”之意，符合语意。through“通过，在……中间”；over “在……的上方”；before“在……之前”，故应选D项。
答案：D
