david get up early --- you will catch the early busa\ butb\andc\ afterd\ or说理由!

david get up early --- you will catch the early busa\ butb\andc\ afterd\ or说理由!
david get up early --- you will catch the early bus
a\ but
b\and
c\ after
d\ or
说理由!

david get up early --- you will catch the early busa\ butb\andc\ afterd\ or说理由!
选B
but,表示转折,意思为,DAVID早点起,但是你将赶上最早的车,寓意不通
and,表示并且,意思为,DAVID早点起,并且你将赶上最早的车.通顺
after,表示之后,意思为,DAVID早点起,之后你将赶上最早的车,寓意不通.
or,表示或者,意思为,DAVID早点起,或者你将赶上最早的车,寓意不通.

B
DAVID,快起来，那样才能赶上车