一艘轮船顺流航行98千米、逆流航行42千米时共用了8小时；当这艘轮船顺流航行72千米、逆流航行108千米时共用了12小时．问此艘轮船的速度是多少？如果两个码头相距315千米，则轮船往返一次需要多少小时？
下列字注音完全正确的的一项是（ ）
My House
I am Jenny. Look! This is my house. What's in the house? Let me show you the rooms. This is the kitchen. Here is the bathroom. That is the living room. Here is my bedroom. That is Danny's bedroom. His bedroom is very nice.
——Be quiet! Mr Smith is coming.——Don't worry. It__________be him. Mr Smith is much taller.
