let down: 使...失望
I feel let down by his indifference.
他的漠不關心使我感到失望。
He won't let you down; he's reliable.
他值得信賴,不會讓你失望。
aggressive: 主動地
His style of argument in meetings is not so much aggressive as pertinacious.
他在會議上的辯論態度并非鋒芒逼人而是堅持己見。
Red fire ants are very aggressive and readily attack anything that disturb them.
紅火蟻攻擊性強,容易攻擊任何干擾它們的生物。
n. 缺點,過失,故障,毛病,過錯,[地]斷層