Eng

Puzzle...

困

Difficult, Hard, Perplex, Poor, Puzzle, Weary

困擾

Confuse, Confused, Nag, Perplex, Perplexed, Puzzle, Puzzled, Troubled

疑難

Problem, Puzzle, Question

謎題

Puzzle

難題

Challenge, Problem, Puzzle

拼圖

Jigsaw, Puzzle