In the near future, professors will run their courses over digital platforms capable of collecting data on each student’s progress. These platforms were initially developed for massive open online courses. However, universities are now folding these platforms back into their traditional classes because they make it easier to share content, host discussions and keep track of student work.Soon, they will be able to monitor which students are spending 15 minutes on a calculus problem and which ones slog away for an hour. This can raise red flags for professors about who might need extra help.As more classes move partially or entirely online, the requirements of having a uniform start and end date diminish. It means some students could sail through a semester’s worth of classes in a few weeks and then start again with new courses.It used to be that getting accepted to a prestigious university was how you accessed the best professors and could hang out with the smartest students. That’s because universities were, for the most part, closed information systems that doled out their content to a select few. That’s changing.

甲是某材料供应公司的法定代表人，董事会授权其可立1000万元以下的合同。甲与某施工企业订立了2000万元的合同，施工企业不知其超越权限。该合同的效力状态为（ ）。

A．不成立

B．无效

C．可撤销

D．效力待定