A:所含质子数=A﹣n
B:质子数=Z+A
C:所含电子数=Z+n
D:所含中子数=A﹣Z
当肋间肌和隔肌收缩时,下列各项正确的是( )
①胸腔容积缩小;②胸腔容积扩大;③肺收缩;④肺扩张;⑤肺内气压低于大气压;⑥肺内气压高于大气压.
①Alice what ten play ping-pong your friend a fat teacher
②Is she a tall girl? No,she isn't. She's a short girl.