13. A long-standing theory about the migration of green turtles was ______ by an innovative marine biologist who graciously defused potential ______ by dedicating her work to the original researcher.
A. instigated, rancor
B. renounced, approval
C. displaced, attribution
D. enhanced, alteration
E. repudiated, acrimony

14. Most pionners ______ this valley on their journey to the West because its rugged terrain and frequent landslides made it a ______ place for travelers.
A. flanked, fascinating
B. avoided, necessary
C. encomppassed, curious
D. enjoyed, troublesome
E. skirted, hazardous

来源:可可英语 //m.moreplr.com/sat/201403/282411.shtml