The infantry: hard, bare feet rhythmically kicking up the dust.
出自: E. WaughEnglish muffins which had been toasted in the morning and were as hard as cement.
出自: E. HardwickThis is a hard question to answer.
这是个难题,不好回答。
This food is hard of digestion.
这个食物很难消化。
It is hard, if not impossible.
这个表达是错误的。