1.隐藏类有哪些方式 2.z-index 3.定位、定位原点、sticky 4.媒介查询 media 5.响应适配 6.原型考察 7.promise实现settimeout 或 同步实现settimeout 8.async/await 9. let obj = {a:1,b:2} function fn1(obj){ obj.a = 10 console.log(obj) } function fn2(obj){ obj = 10 console.lo...