He was heading for a ______ inland area in the north-east, a region a flat endless landscape of black earth, dotted with primitive cottages made of sods of turf and sticks.

A．existing
B．accessible
C．exhaustless
D．abundant

A. He must be in the office now.
B. He must shoulder such a responsibility.
C. He must have slept late last night.
D. He must be feeling sorrowful.