Show off: to try to impress others by talking about your abilities, possessions, etc. 炫耀自己;卖弄自己
He's just showing off because that girl he likes is here.
他不过是在表现自己,因为他喜欢的那个姑娘在场.
Bear in mind: 记住
Bear in mind that you'll have to practice economy.
记住要厉行节约.