— Who is singing in the next room?
— It be Lucy. She likes singing at this time.
A:can
B:must
C:mustn't
D:should
如图所示玻璃管两端开口处蒙的橡皮膜绷紧程度相同,将此装置置于水中,下列哪幅图能反应橡皮膜受到水的压强后的凹凸情况( )
跨经度最多的大洲是( )