Itriedtocallyou____Iheardfromhim,butyouwerenotin.
a.sinceb.whilec.untild.assoonas
为什么答案选D
Workhard,_____youmaycatchupwithyourclassmatessoon.
a.orb.butc.andd.yet
为什么选C
Iwasdrawingahorse_____theteachercamein.
a.whileb.asc.whend.themoment