哪一项不是颅内压增高所致头颅x线平片特点()
A.颅缝裂开
B.枕大孔扩大
C.脑回压迹加深
D.蝶鞍扩大,前后床突骨质吸收
E.蛛网膜颗粒加深
参考答案:B
In many countries, teenagers under 18 should not ______ to enter Internet bars. [ ]
A. allow
B. be allowed
C. is allowing
D. are allowed
50g质量分数为36.5%的盐酸与30g大理石恰好完全反应(大理石中的杂质不参加反应).
(1)计算反应生成二氧化碳气体的质量.
(2)计算该大理石中碳酸钙的质量分数.