It’s really difficult to what he is trying to express.
A. leave out
B. break out
C. put out
D. make out
网友回答
A. leave out
B. break out
C. put out
(答案→)D. make out
解析： 词义辨析。leave out 遗漏，省略；break out爆发；put out 拿出，出版；make out弄清楚，弄明白。句意：很难弄明白他到底要表达什么意思。所以选D。