How to say "please enter your password" in Mandarin
I used to regularly encounter the phrase "please enter your 
password" in Chinese when I used phone cards (like the one on the right) in China. By the way, the word for phone is 电话, pronounced dian4 hua4. 电 means "electric" and 话 means "speech" so telephone is "electric speech", which makes sense. The word for "phone card" is 电话卡, where 卡 (ka3) means card. Actually, 卡 means calorie, card, casette and truck, but who's counting.
The automated phone card lady used to say 请输入密码 = qing3 shu1 ru4 mi4 ma3 = please enter your password.
The first word is 请, pronounced qing3, which means "please". The second word is 输入, pronounced shu1 ru4, which means "input" or "import". The final word is 密码, which sounds like mi4 ma3, and means "secret code" or "password".