俗话说:‘十指连心”,这说明皮肤中含有( )
A:触压觉感受器
B:痛觉感受器
C:冷觉感受器
D:热觉感受器
如图,四边形ABCD内接于⊙O,若它的一个外角∠DCE=70°,则∠BOD=( )
一汽车在平直公路上行驶,其位移x(m)随时间t(s)变化的规律为:x=25t﹣ 52 t2,则汽车行驶3s后速度为____ m/s,5s内汽车位移为____ m.
—What were you doing when the earthquake happened in Jianhe ? —I morning exercises.
This idea sounds as as that one.
—Which of the two subjects do you like, PE or music?—— . They are really interesting.