The explorers have to be very ________ to endure the hardships．

The explorers have to be very ________ to endure the hardships．

A.rough

B.brave

C.patient

D.tough

答案及解析： D

rough意为“粗糙的，不平的”；brave意为“勇敢的”；patient意为“耐心的”；tough意为“坚韧的，能吃苦耐劳的”。