题目

“You're going to the doctor，”your mum tells you. But why go to the doctor when you're not sick？Regular checkups（健康检查）are a good idea for kids. These visits happen when you're feeling fine and are sometimes called “well-child” visits because you're well. It's a chance for the doctor to see that you're growing and developing normally. It's also a chance for your parents to talk with the doctor about any issues，such as safety or nutrition，so they can help you stay healthy. And it gives you a chance to ask any question you might have about your health. You might wonder 如图所示，是在A点画出吊起重物G所用最小的力和这个力的力臂。