He found it increasingly difficult to read, ______ his eyesight was beginning to fail.
A. though B. for C. but D. so
He found it increasingly difficult to read, ______ his eyesight was beginning to fail.
A. though B. for C. but D. so
B
句意: 由于他的视力开始下降, 他发现读书越来越困难了。本题句子前后是因果关系, for的意思是“由于、因为”; though引导的是让步状语从句, 意思是“虽然……但是……”; but的意思是“但是”, 表示转折; so的意思是“因此、因而”, 在句意上不通。所以选B项。