下列各数中,不是无理数的是 ( )
A:7
B:0.5
C:2π
D:0.151151115······
自然界只有正、负两种电荷,我们把用绸子摩擦过的玻璃棒带的电荷叫做____ ,同种电荷相互____
Some children prefer to eat junk food ________ it's not good for their health.