现象
解释
A.
量筒内气体颜色逐渐变浅
甲烷被氯气还原
B.
量筒内出现少量白雾
生成HCl气体
C.
量筒内壁产生油状液滴
油状液体是CCl4
D.
量筒中液面降低
生成液态产物
A:A
B:B
C:C
D:D
Jim tried his best to raise his spirits though he failed the exam.
抛物线x2=4y的焦点坐标是( )
Time goes by so fast . We must never miss the chance to show love for our parents and make them _____ how much they mean to us .