找出句中错误的一项.1.The red bag is cheapest of all the bags 2.Let's

找出句中错误的一项.
1.The red bag is cheapest of all the bags 2.Let's leave school at five ten in Saturday 3.Bruce lives on the twelve floor.He uses a lift up and down 4.Jane's hair is much longer than her mother 5.Miss Zhang is one of the busiest teacher