题干
Last week I met my old friend Li Ming by accident but I forgot _______ him for his telephone number.
A：ask
B：asking
C：asks
D：to ask
答案(点此获取答案解析）
D
Last week I met my old friend Li Ming by accident but I forgot _______ him for his telephone number.
A：ask
B：asking
C：asks
D：to ask
为某原子的结构示意图，该原子中有