题目

 I will tell him the good news as soon as he____ back. A. come         B. comes                 C. came                D. will come 答案：B一个圆的半径是2dm．它的直径是　 　；一个圆的直径是6cm，它的半径是　 　；一个圆的半径是6cm，它的直径是　 　．