如果一个多边形的内角和是1800°,那么这个多边形的边数是______.
这个正多边形的边数是n,
则(n-2)•180°=1800°,
解得:n=12,
则这个正多边形是12.
How I wish that you could attend the party, even though you ________ busy. [ ]
A. had been
B. would be
C. were
D. are
某种药物主要成分X的分子结构如图:关于有机物X的说法中,错误的是
A.X难溶于水,易溶于有机溶剂
B.X不能跟溴水反应
C.X能使酸性高锰酸钾溶液褪色
D.X的水解产物能发生消去反应