食管下段局限性不规则收缩称为
C
暂无解析
设函数y=e^x+1，则y''=（）
(33)43+(37)47的个位数是多少?
求函数f(x)=x^3-3x^-9x+2的单调区间和极值.
Inordertolivethekindoflifewewantandtobethepersonwewanttobe，wehavetodomorethanjust________withevents．
You'veonlygotaslightcold.You'll_____itinadayortwo.
