Tutorial tu13.04 difficult questions

For more information, see ubuntu13.04. Linux general technology-Linux technology and application. Ubuntu has several difficult problems to solve.
1. user password ??? ? 0 days? Fierce? More. (From? Even though I have swallowed up the mystery, I have expired and changed it )??? To? Yes? Set to expiration. And? Set the reminder seven days before expiration.
Expired?] Yes ???. But the last seven days are not ?? Why? However, the computer will be locked in 30 days. To be reminded, you need to set it separately.

2. password ?? Degrees ?? Liao ??? Character. The setting location is found, but the setting does not work.
PASS_MIN_LEN 7
PASS_MAX_LEN 12

3. password? Required? Contains at least one ?? Letter and ?? Special characters and one ??? Bottom rank? N characters? .

4. the same password cannot be used for several login accounts.

5 .?? ? When does one have? V Cheng ???? O is set to 4 times ??? Password ?. PS: The password set this time cannot be the same as the password set in the previous four times.

6. heavy? Login ??? Password ?? 3 times ,?? I live user? Why ?.