動詞 come in handy:

1. be useful for a certain purpose

1. Do not throw that plastic bag away; it may come in handy.
   別把那個塑膠袋扔了，會用得著的。
2. Don't throw that cardboard box away it may come in handy.
   不要把那個紙盒丟掉--可能用得著。
3. These books will come in handy.
   這些書將來會有用的。
4. A few more traveller's cheques may come in handy on the holiday.
   多帶幾張旅行支票，度假時會有用的。