GRE Text Completion: ETS Fundamental-GRE填空ETS基础 - T47U4II1XVOYX4OIX

Number theory is rich in problems of an especially (i)____________ sort: they are tantalizingly simple to state but (ii)____________ difficult to solve. A. spurious B. deceptively C. elegant D. ostensibly E. vexing F. notoriously