题干
It's hard ______ me ______ Chinese chess.
A：of; playing
B：for; playing
C：for; to play
答案(点此获取答案解析）
C
It's hard ______ me ______ Chinese chess.
A：of; playing
B：for; playing
C：for; to play
成等比数列，
是
与
的等差中项，
是
的等差中项，则
（ ）