Dear Mum and Dad,

    How are you? I'm happy 1 America. It's cool here. What is the 2 like in London? Uncle Bob and Aunt Jenny are nice to 3. This is Uncle Bob and Aunt Jenny's  4, Toby. He is thirteen years old. We are good friends now. We 5 basketball every day. Tomorrow 6 Saturday. Uncle Bob and Aunt Jenny want to take Toby and me to the Haines Shoe House. It is a 7. It is 67 years old. Here is a 8 of it. There are two bedrooms, one kitchen 9 one living room. There is an ice cream shop in it too. I love ice cream! Are there 10 computers or TVs in the hotel? I will find it out (查明) tomorrow.

如图，小华用不计重力的弹簧测力计拉着一物块以2 m/s的速度在水平地面上匀速前进，弹簧测力计的读数为____N，物块受到的滑动摩擦力的大小为 ____N；当速度增加到4 m/s时，物块受到的滑动摩擦力的大小为 ____N

植物细胞和动物细胞都具有的能量转换器是（   ）