Many of them turn a deaf ear to his advice, they knew it to be valuable.
A. as if
B. now that
C. even though
D. so that
网友回答
A. as if
B. now that
(答案→)C. even though
D. so that
解析：even though 引导让步状语从句，意为“尽管”，表示“尽管他们知道他的建议很有价值，但许多人都不理会”。as if意为“好像”。now that意为“既然”。so that意为“以便”。