【单选题】

When a friend was visitingDavid, it began (41) . SoDavid told him (42) that night. "You may stay here (43) the night," he saiD、"OK", answered his frienD、

But (44) minutes (45) , the friend went out. He didn’t tellDavid where (46) going nor (也没有) did he ask for an umbrellA、
WhenDavid was about (47) , his friend (48) . He was all wet through.
"Where (49) you (49) "askedDaviD、
"I have been (50) "answered the friend, "to tell my mother that I’ll not go home tonight because of the rain.\
A、for B、to C、of