1.These are just a few methods that were designed to replace the pumicing procedure.
这只是几种专门替代浮石粉的方法。
2.We found that this is the best alternative to pumicing .
我们认为这是替代浮石粉填孔的最好方法。
3.With practice, this is also a good alternative to pumicing but takes much longer.
随着熟练，这也是代替浮石粉的好方法，只是需要更多时间。