2010ÄêÖп¼Ó¢Óï±±¾©Ò»Ä£½âÃÜÔ¤²âÊÔÌâ4
´ÓA¡¢B¡¢C¡¢DËĸöÑ¡ÏîÖУ¬Ñ¡³ö¿ÉÒÔÌîÈë¿Õ°×´¦µÄ×î¼ÑÑ¡Ïî¡£
21. Yesterday ______ 11-year-old boy fell into the river. Luckily _____ boy was saved by his neighbour at once.
A. a; a B. an; a C. an; the D. the; a