吃饭时不能说笑的原因是( )
A:流经消化器官的血流量减少
B:食物易从咽误入气管
C:消化腺的分泌能力下降
D:肺内压小于大气压
唐代长安城 宋代东京城
—Do you know why the teacher asks for me?
—He wants you to _____ your absence last night.
为调查可变性红斑角化症遗传方式并绘制遗传系谱图,下列说法正确的是( )
— _________ my dictionary? I can't find it anywhere.
— I ________ it on the shelf when I came in.