A:a的向心加速度等于重力加速度g
B:b在相同时间内转过的弧长最长
C:c在4小时内转过的圆心角是π/6
D:d的运动周期有可能是20小时
读我国四个省级行政区轮廓图,如图四省中,濒临我国渤海的省区是( )
(____) I'm looking out of the window.
(____) Some children are making a snowman.
(____) In this photo,we are in the mountains.
(____) The wind is blowing and the sun is shining.
(____) I am having a lovely time.