冷哮之痰是
A.痰脓腥臭B.痰稠黄胶结C.痰稀薄多沫或痰白而黏D.痰少黏稠难出E.痰如白沫量多
参考答案:C
质点做直线运动,其位移随时间变化的函数关系是s=4t+2t2(s的单位为m,t的单位为s),则它运动的初速度v0和加速度a分别是( )
A.v0=0,a=4m/s2
B.v0=4m/s,a=2m/s2
C.v0=4m/s,a=1m/s2
D.v0=4m/s,a=4m/s2
---There is some doubt _____ the concert will be held as the company intends to redecorate the stadium next week.
---What a pity!
A.where
B.that
C.if
D.how