用so long as, as long as造句，写明用法．

1.当用于同级比较时，as .....as 既可用于肯定中也可用于否定句中，
而so....as 只能用于否定句中。
His pencil is as long as mine.
His pencil isn't so/as long as mine.
2.当表示只要时，两者没有什么区别，可以替换。
e.g.Our profits will be good as/so long as the dollar remains strong.