Drug Resistancet Fades Quickly in Key Aids2 Drug　　One of the main weapons to prevent mother-to-child transmission of the AIDS virus during birth is the drug nevirapine3. But when nevirapine is used alone just once, HIV4 starts becoming resistant to it. Research in Botswana shows that the resistance is not long lasting and that this affordable drug does not have to be abandoned forever by infected mothers who have already taken it.　　The problem is that HIV resistance builds against it quickly when used alone just once because other drugs are not present to kill the virus particles that survive nevirapine. This renders the drug less effective in later combinations for treating women after their baby is born. But the new study from Botswana shows that nevirapine can make a comeback for these women if they wait until the resistance subsides.　　The study published in the New England Journal oJ Medicine9 shows that waiting at least six months means that HIV-positive women are 70 percent more likely to benefit from nevirapine-based drug combinations again than women who get them sooner. An official with the U.S. government health agency that helped fund the study calls it very important.www.zcyy8.CoM　　Shahin Lockman in Boston says the problem of nevirapine resistance should diminish now that12 more and more people are receiving combinations of AIDS drugs under expanded U. S. and international programs to deliver them to Africa and other regions hard hit by the virus.　　1. What effect does nevirapine have?　　B It is an antiviral preparation and kills all kinds of viruses.　　D It may prevent passing HIV infection from mothers on to their newborns during delivery.　　A Because the drug is not strong enough to kill all of the HIV in the body.　　C Because other drugs are not present to kill the virus particles that survive nevirapine.　　3. When may a woman start her nevirapine-based treatment if she gets the single dose of nevirapine at delivery ?　　B She may start nevirapine-based treatment within six months after her delivery.　　D She may wait several years so as to achieve the best effect.　　A lasts only for about a half year and fades quickly.　　C is a terrible drug that must be banned at once.　　5. Generally speaking, the authors attitude towards the use of nevirapine is　　B positive　　D doubtful

　　Drug Resistancet Fades Quickly in Key Aids2 Drug　　One of the main weapons to prevent mother-to-child transmission of the AIDS virus during birth is the drug nevirapine3. But when nevirapine is used alone just once, HIV4 starts becoming resistant to it. Research in Botswana shows that the resistance is not long lasting and that this affordable drug does not have to be abandoned forever by infected mothers who have already taken it.　　The problem is that HIV resistance builds against it quickly when used alone just once because other drugs are not present to kill the virus particles that survive nevirapine. This renders the drug less effective in later combinations for treating women after their baby is born. But the new study from Botswana shows that nevirapine can make a comeback for these women if they wait until the resistance subsides.　　The study published in the New England Journal oJ Medicine9 shows that waiting at least six months means that HIV-positive women are 70 percent more likely to benefit from nevirapine-based drug combinations again than women who get them sooner. An official with the U.S. government health agency that helped fund the study calls it very important.www.zcyy8.CoM　　Shahin Lockman in Boston says the problem of nevirapine resistance should diminish now that12 more and more people are receiving combinations of AIDS drugs under expanded U. S. and international programs to deliver them to Africa and other regions hard hit by the virus.　　1. What effect does nevirapine have?　　B It is an antiviral preparation and kills all kinds of viruses.　　D It may prevent passing HIV infection from mothers on to their newborns during delivery.　　A Because the drug is not strong enough to kill all of the HIV in the body.　　C Because other drugs are not present to kill the virus particles that survive nevirapine.　　3. When may a woman start her nevirapine-based treatment if she gets the single dose of nevirapine at delivery ?　　B She may start nevirapine-based treatment within six months after her delivery.　　D She may wait several years so as to achieve the best effect.　　A lasts only for about a half year and fades quickly.　　C is a terrible drug that must be banned at once.　　5. Generally speaking, the authors attitude towards the use of nevirapine is　　B positive　　D doubtful