Making the world better, one answer at a time. a superbug is a micro-organism that is resistant to most anti-biotics. the superbugs in recent history are imune to all anti-biotics,except one.
Both electronic and paper versions of Series I savings bonds are purchased at face value and earn interest until they are redeemed or reach maturity. You must hold Series I bonds for at least 12 months before redeeming them. Series I savings bonds will continue to earn interest for up to 30 years. They will cease paying interest once they have matured.
If a bond does not double in value as the result of applying the fixed rate for 20 years, the U.S. Treasury will make a one-time adjustment at original maturity to make up the difference. Series EE bonds earn interest for 30 years.. Source(s): http://www.treasurydirect.gov/indiv/rese...