to understand or solve the real cause of something
了解或解决某事的真正原因 (liaojie huo jiejue mou shi de zhenzheng yuanyin)
"We need to get to the bottom of this issue to prevent it from happening again."
"我们需要弄清这个问题的真正原因，以防再次发生。" (women xuyao nongqing zhege wenti de zhenzheng yuanyin yi fang zaici fasheng)
to buy something that is defective or worthless
two people who used to dislike each other but became friends
to have ambitious goals and aspirations
to be open and honest in your actions
to think about only one thing all the time
to change direction or strategy quickly
