http://www.grad.ncsu.edu/catalog/prg.asp?id=EE
写的是
The minimum acceptable TOEFL score for admission to the Ph.D. program is 90 (minimum 18 in each area, with minimum of 19 on Speaking).
http://www.ece.ncsu.edu/graduate/admissions
写的是. 1point3acres.com
On the TOEFL iBT, students must have a minimum of 18 on each section of the test with a minimum total of 90.