A:所含质子数=' A-n'
B:所含中子数=A-Z
C:所含电子数='Z+n'
D:质量数=Z+A
直线y=kx+3与圆x-32+y-22=4相交于M,N两点,且MN≥23,则k的取值范围是( )
蛙的发育是变态发育,它的幼体区别于成体的显著特征是( )
An orange is a little ____ (big) than an apple, but much ____ (small) than a watermelon.
写出小面各小数的近似数
保留一位小数
4.59≈____ 0.098≈____