alert, cautious, considerate这一组形容词都表示“小心的，谨慎的”。
alert a.警惕的，留神的。
the hostess remained standing, alert to every guest's drinking need.
女主人一直站在旁边，时刻准备给大家斟酒。
cautious a.细心的，谨慎的。
he has a cautious attitude about spending money.
在花钱的问题上他态度谨慎。
considerate a.关心他人的，体贴的。
he is always considerate of others; he is kind and sympathetic.
他总是很体谅他人，并且慈祥而富有同情心。
since not everybody is so considerate, do what you can to stay healthy.
鉴于不是每个人都这么体贴，你要做任何可以让自己保持健康的事情。
he expressed gratitude to the king for his warm reception and considerate arrangement.
他对国王陛下的热情款待和周到安排表示衷心感谢。