He is a jack of all trades and master of none.

他样样都懂一点，但都不精通。

youdao

My prediction: Apple's tablet will be Jack of trades and master of none.

我的预言是：苹果的平板将会是一个什么都会但没一样精通的设备（Jack of all trades master of none）。

youdao

Answer: The Druid was designed as a "Jack of All Trades" type of character - good at many things yet master of none.

回答：因为德鲁伊是被设计成一个“万金油”型的角色——擅长很多东西却都不精通。

youdao

Critics contend that the LCS is a jack of all trades that will be master of none, but its supporters are convinced its flexibility will make it a success.

ECONOMIST: Military technology

Generalists are often derided as a jack of all trades, master of none, yet their broad thinking and diverse interests enable the integration of ideas that leads to true breakthroughs.

FORBES: The Connection Between Creative And Crazy

Today, the Christmas song is a holiday standard with over 1, 500 renditions since it was first recorded, but none of them quite reach the master's version.

NPR: Nat King Cole's 'The Christmas Song'