Bto seeing
witness to
to 是介词.
1.(为…)作证：
He witnessed to having seen the accused kill the boy.
他作证说曾看到被告杀了那男孩.
The girl witnesed __the man burst into the bank on a night yesterday
那个女孩子作证说曾看到,那个男人,昨天晚上闯进银行.