3:15 pm means __________.
A:a quarter past three in the afternoon
B:a quarter past three in the morning
C:a quarter to four in the evening
D:a quarter to three in the afternoon
如图所示,线框ABCD从有界的匀强磁场区域穿过,下列说法中正确的是( )
如图为模拟膈肌运动的示意图,下列叙述正确的是( )