The major disadvantages of the current learning methods are: (1) one-type costassumption is not agreed with the actual case where there usually exist several types of costs;
这些学习方法存在的主要缺点有：（1）单一代价假设不符合现实存在的多种代价的实际情况；
2
The assumption that many of us made at the time was that edi, because of cost, was going to fade away in the short to medium term.
在当时，我们很多人做出的假设是EDI会由于成本问题，在一段时间内会逐渐消失。
3
I've asked Microsoft to make sure my assumption on low-cost PCs is correct. No word back yet.