问题
选择题
—Susan, what are the advantages of MP5 players?
—Mom, they are smaller and lighter ______ they can be carried very easily.
A.unless
B.if
C.until
D.so that
答案
答案:D
unless除非,如果不;if是否,如果;until 直到;so that以便,所以。句意:苏珊,MP5播放器的优势是什么?——妈妈,它们更小更轻便,所以它们携带非常方便。结合语境可知前后是因果关系,故选D。