原式=a+bab•a(a-b)(a+b)(a-b)=1b.
故答案为1b.
--- After discussing, the students ________ some good ideas to work on the project.
--- That’s great!
A.put up
B.came up with
C.caught up with
D.set up
J. Martin指出,企业模型应具有完整性、适用性和______性。