I spent three hours a day talking to him.为什么用talking?

I spent three hours swimming in the river.为什么用spent?急 I spent three hours a day talking to him.为什么用talking? 一道改为同义句的英语题I spent three hours reading the book（改为同义句）____ ____ ____ three hours ____ ____ the book. I spent three and a half hours doing my work.(改同义句)I spent ____ ____ ____ ____ ____ doing my work. I spent hours _____(do) some reading. 英语翻译He spent three hours walking through the forest 还是：He spent three hours walking through the forest on foot In order not to be disturbed ,I spent three hours _____ in my study .A.locked B.being locked.为什么不选B呢? In order not to be disturbed,I spent three hours locked or locking my study?是填locking or locked?填locking，locked，or being locked I cleaned my classroom(A with three hours Bthree hours ago C in three hours D three hours before)如上 I danced for three hours last I spent two hours doing my homework yesterday什么意思 I spent two hours ____(finish) my homework yesterday. I spent two hours on my homework.同义句 i spent five hours make the model plane.同义句 I spent two hours cleaning my room 改为同义句 I spent two hours in___(finish)this task I spent two hours making the cake.(同义句转换) I spent two hours with my homework.这句话对吗