据报道,欧洲一科学小组发现了第112号元素的质量数为227的同位素,其中子数为
A.114
B.115
C.116
D.117
答案:B
中子数=227-112=115;
一个正多边形的每个外角都等于36 °,则它是( )边形.
He behaves _____ he were better than us.
[ ]
A. even though
B. even if
C. as though
D. although