A:x=21.5
B:x=2.2
C:x=0.3
D:x=1.7
—Sorry, I can't make it. Will three o'clock be OK?
(英汉小词典:right直角的;isosceles等腰的;equilateral等边的;obtuse钝角的)
世界上最大的大陆是 ( )