zhe first aniinsects were mals to live on land ,more than ( )years agoa.four hundereds million b.four hundred million c.four hundredmillions d.four hundred millions of
问题描述：
zhe first aniinsects were mals to live on land ,more than ( )years ago
a.four hundereds million b.four hundred million c.four hundredmillions d.four hundred millions of
答
b