这个英文句子我读不懂,求翻译.

题目

这个英文句子我读不懂,求翻译.
Parents using face-to-face buggies were twice as likely to talk to their children while the heart rates of the babies fell and they were twice as likely to fall asleep, an indicator that they were feeling relaxed and safe.
难点是不是在as从句？以及那个twice,最好能讲解一下用法

答案

我记得这是一个调查里面的
调查的是 面对面的婴儿车 还是用 婴儿背对着父母的婴儿车 有利于婴儿的成长.
上面这句话就是阐述了 父母使用面对面的婴儿车时,更像与他们的孩子在交谈,而此时孩子的心跳更接近他们睡觉时的心跳,这就表明,在这种情况下,孩子感觉到放松和安全.
twice只是一个比较.双倍于,更加
as 就如,就像
twice as合起来,表示更像,更接近,更如