a drop in the ocean == a drop in the bucket 沧海一粟;九牛一毛

• For him, this is a drop in the bucket. 对他而言，这只是九牛一毛。
• It just is a drop in the ocean compared with his salary. 与他的工资相比，这只是九牛一毛。

in the middle of nowhere 在遥远偏僻处

• His parents live in the middle of nowhere. 他父母住在荒无人烟的地方

off the beaten path == off the beaten track 偏僻的; 人迹罕至的

• It is off the beaten track. 这有点偏远。
• Her house is off the beaten path. 她的房子在很偏僻的地方。

be within walking distance of sw 离某地几步之遥

• The school is within walking distance of my home.学校离我家只有数步之遥。

when pigs fly 猪都会飞了；绝对不可能

• He will pop the question to her when pigs fly. 他会向她求婚，母猪都会上树啦。

against all odds 尽管困难重重

• Against all odds, she still completed the project on time. 尽管困难重重，她还是按时完成了项目。

like shooting fish in a barrel 如瓮中捉鳖般，如同探囊取物般简单

• It's like shooting fish in a barrel. 这就如探囊取物般简单。

be a tall order 很难做到的事；棘手的事

• It's a tall order for the newbie. 对新手来说，这是一件很难做到的事。

be out of sb's depth 某人无法胜任的；无法驾驭的

• The task is out of my depth. 这个人物超出了我的能力范围。

have eyes in the back of sb's head 某人背后长了眼睛；目光敏锐，什么都能觉察到

• Parents need to have eyes in the back of their head, knowing what their kids are doing. 父母需要像背后长了眼睛一样，知道他们的孩子正在做什么。