A:31℃
B:19℃
C:﹣31℃
D:﹣19℃
天平两端分别放置盛有足量稀盐酸的烧杯,把天平调至平衡,现向其中一只烧杯中投入10g碳酸钙,向另一只烧杯中投入适量Al片,要使天平最终保持平衡,投入Al片的质量为____ g :
下下列各项中,没有语病的一项是( )
Shengzhou Ⅶ has been ____ (success) set up into the space.
Don't stand too close to North Americans. You'd better give them more personal ___ .