英语翻译Some linguists say children are greatly diffrent in the amount of listening that they do before they star speaking.顺便问下,为什么用that?

英语翻译
Some linguists say children are greatly diffrent in the amount of listening that they do before they star speaking.顺便问下,为什么用that?

某些语言学家表示不同孩子在能开口说话之前所接收的听力量有很大的差别.