______ ______ ______babies usually sleep every day?该如何填?原句是:Babies usually sleep 18 hours every day.对画线部分提问.________

问题描述:

______ ______ ______babies usually sleep every day?该如何填?
原句是:Babies usually sleep 18 hours every day.对画线部分提问.
________

How long do babies usually sleep every day?