For investors who desire low risk and guaranteed income, US government bonds are a secure investment because these bonds have the financial backing and full faith and credit of the federal government. Municipal bonds, also secure, are offered by local governments and often have（1 ） such as tax-free interest. Some may even be（2）. Corporate bonds are a bit more risky.
      Two questions often（3）first-time corporate bond investors. The first is "If I purchase acorporate bond, do I have to hold it until the maturity date?" The answer is no. Bonds are bought and sold daily on（4） securities exchanges. However, if you decide to sell your bond before its maturity date,you're not guaranteed to get the face value of the bond. For example, if your bond does not have  （5） that make it attractive to other investors, you may be forced to sell your bond at a （6）,i.e., a price less than the bond's face value. But if your bond is highly valued by other investors, you maybe able to sell it at a premium, i. e., a price above its face value. Bond prices generally （7）inversely (相反地) with current market interest rates. As interest rates go up, bond prices fall, and viceversa (反之亦然). Thus, like all investments, bonds have a degree of risk.
     The second question is "How can I （8）the investment risk of a particular bond issue?"Standard & Poor's and Moody's Investors Service rate the level of risk of many corporate and government bonds. And（9）, the higher the market risk of a bond, the higher the interest rate. Investors will invest in a bond considered risky only if the（10） return is high enough.

A.advantages          
B.assess             
C.bother              
D.conserved          
E.deduction
F.discount
G.sembarras 
H.features 
I.fluctuate  
J.indefinite   
K.insured 
L.major 
M.naturally
N.potential
O.simultaneously