it is great. my children usually stay up late in bed singing random songs and taking turns keeping each other awake, but when we discovered this they fell asleep quickly and didnt wake up in the middle of the night to bug me.
太好了。我的孩子們經常在床上很晚才睡，唱著隨機的歌曲，輪流讓彼此保持清醒，但是當我們發現這一個時，他們很快就睡著了，並沒有在半夜醒來來打擾我。
