单项选择题
Directions: For each numbered blank in the following passage there are four choices labeled [A], [B], [C], and [D]. Choose the most suitable one.
The use of such phrases as “Good morning” or “Pleased to meet you”, and ritual exchanges about health or the weather, do not communicate ideas in the usual sense, but hardly to maintain a comfortable relationship between people. Sentences of this kind are usually _____ produced, and stereotyped in structure.
A.artificially
B.efficiently
C.accidentally
D.automatically