hidden ·adjective (NOT KNOW ABOUT)

这份合同有许多隐性成本，所以最终账单比预期的要高得多。

The contract had many ___hidden costs, so the final bill was much higher than expected.

哈利在会议上有一个隐藏的议程，并决心要按他的方式来。

Harry had a ___hidden agenda at the meeting and was determined to get his way.

我认为这是拥有手机的一个潜在危险。

I think this is a ___hidden danger of having a mobile phone.