Now he introduced a completely unprecedented ad hoc assumption whose only justification was a pragmatic one-it worked . 现在他引入一个史无前例的特殊假设，它的唯一理由完全是实用主义的--那就是它管用。
2.
Now he introduced a completely unprecedented ad hoc assumption whose only justification was a pragmatic one - it worked 现在他引入一个史无前例的特殊假设，它的唯一理由完全是实用主义的- -那就是它管用。
