问答题 XeF2分子稳定构型为（  ）型

单项选择题 Economists agree that A、neither high inflation nor moderate inflation is very costly. B、both high and moderate inflation are quite costly. C、high inflation is costly, but they disagree about the costs of moderate inflation. D、moderate inflation is as costly as high inflation.

判断题 原子所能形成的共价键数目等于原子核外的未成对电子数。