— Ben, what's your favorite subject, math ________ science?
— Math.
A:and
B:or
C:but
D:so
The room was dark, so she asked me to _________ the lights.
法国作家雨果说:“世界上最广阔的是海洋,比海洋更广阔的是天空,比天空更广阔的是人的胸怀”。这告诉我们做一个有教养的人,要( )
____和____这两个生态因素的共同作用决定着生物群落在地球表面分布的总格局.
________ the job takes a significant amount of time, most students agree that the experience is worth it.
如图是人体心脏结构模式图,请回答有关问题: