回答

・sleep like a log
・fast asleep

「熟睡」可以用英語 sleep like a log 或 fast asleep 來表達。

Could it be that someone is sleeping like a log in the next room?
（隔壁房間，難道有人正在熟睡？）

It seems that my smartphone has been called many times since a while ago, but I didn't notice it at all because I was fast asleep.
（不久前我的手機似乎有許多來電，但因為我睡得很熟，完全没注意到。）

希望可供你參考。

有幫助｜0