能用Macbook Pro或者Retina Macbook Pro的充电器给Macbook Air充电吗？一个功率是45w，一个是85w(13’的是60w)，可以还是不可以？
Power adapters for Intel-based Apple notebooks are available in 45W, 60W, and 85W varieties. Although you should always use the proper wattage adapter for your Apple notebook, you can use an adapter of a higher wattage without issue.
For instance If you have a MacBook (13-inch Late 2009) that normally uses a 60W adapter, you can also use an 85W adapter with that computer. You would not use a 45W adapter with that computer; it would not provide enough power for that MacBook.
Using an adapter of higher wattage than the adapter that came with the computer will not cause the computer to charge more quickly or otherwise operate any differently than using the adapter that came with the computer. The tables further down in this article show the style of connector that initially shipped with each model of MacBook, MacBook Pro, and MacBook Air.