在侧位胸片上，心后下缘与食管前间隙狭窄或者消失，提示（）
A.左房大
B.左室大
C.右房大
D.右室大
E.右心衰竭
参考答案：B
等腰三角形的腰长为3，底边长为2，则底角的余弦值为 .
The fat man doesn't have _____ money. [ ]
A. few
B. much
C. a lot
D. a few
