2 sentences

1. 他把事情的底细全兜了出来。

   tā bǎ shì​qing de dǐ​xì quán dōu le chu​lai.

   He spilled all the details of the matter.

   Source: Dong Chinese Dictionary

2. 在和他做生意之前，你最好先摸清他的底细。

   zài hé tā zuò shēng​yi zhī​qián, nǐ zuì hǎo xiān mō​qīng tā de dǐ​xì.

   Before doing business with him, you'd better find out about his background.

   Source: Dong Chinese Dictionary