They typically have very high fixed costs of research and development and low marginal costs of adding additional users.
它们仅仅具有很高的用于研发的固定成本和极低的由新增服用者引发的边际成本。
2
The big gap between the headline and effective marginal taxrates reflects the large number of allowances given to firms for doingparticular activities, such as research and development.
法定税率和有效边际税率的巨大差异反映了各国种类繁多的优惠政策，比如补贴研发项目等等。
3
Second, a basic development plan should be found for a prospect with marginal economy in the block evaluated, and then a parameterization should be made for the plan.