He be sitting at the gate, waiting for his lost son.
A. used to
B. was used to
C. could
D. was accustomed
网友回答
(答案→)A. used to
B. was used to
C. could
D. was accustomed
解析：句意：他过去常常坐在门口，等候他的失踪的儿子。used to do过去常常；was used to doing习惯于；was used to do被用来；could能够；be accustomed to doing 习惯于。根据句意故选A。