Everyone ________ go through the security check（安检）when entering the World Expo Park.
A：can
B：may
C：must
D：ought
I punished my son for his fault this morning.But I would rather not________it；after all，he is only 5 years old.
与240÷48结果相等的是( )。
下列生物中，亲缘关系最近的是（ ）
