大海捞针的英文：
[Literal Meaning]
big/sea/pick up/needle
to look for a needle in the ocean

[解释]
在大海里捞一根针，比喻很难找到。

[Explanation]
to look for something that is impossible to find

[例子]
警方说要从这么大的城市中找一个人，仿佛是大海捞针。

[Example]
The police said finding a person in a mega city like this will be like looking for a needle in the ocean.

[英语等价词]
like looking for a needle in a haystack

Look for a needle in a Bundle (or bottle) of hay
大海捞针

Searching for a needle in a haystack
大海捞针

Look for a needle in a haystack
大海捞针

It was like fishing for a needle in the ocean.
这犹如大海捞针一般。

Searching for one man in this big city is like looking for a needle in a haystack
在这座大城市里寻找一个人犹如大海捞针

There is no use searching for him in this crowd;it is like looking for a needle in a haystack.
在这样的人群中找寻他是徒劳的，这简直是大海捞针。

You can never find him in such a large crowd of people. You're looking for a needle in a haystack.
"在这么大群人里你不可能找到他,你简直是在大海捞针。"

Finding music that matches your tastes can be hit or miss.
在乐海了里寻找合自己口味的音乐简直就像大海捞针,只能是碰碰运气。

Trying to find a pen that works in this house is like trying to find a needle in a haystack.
要想在这间房子里找到一支可用的钢笔，这如同大海捞针。