difficulty比較級

difficulty是名詞，沒有比較級，一般比較級是指形容詞或副詞才有比較急。

那麼difficulty名次的形容詞變體是difficult，difficult的比較級是more difficult表示更難的，例如：

1、While the top of the ocean is well studied， its depths are more difficult to explore.雖然海洋表面已得到了充分的研究，但深海更難探索。

2、Exercise energizes you， so it is more difficult to relax and have a peaceful sleep when you are very excited ．運動使你精力充沛，所以當你非常興奮的時候會更難放鬆和進入睡眠。