Their safety is dangerous when they don't use a common measurement is because they don't know what are safe amounts of this dangerous chemical for them to use. Because they're using dangerous chemicals without a common measurement - this obviously puts them at risk.
I don’t know 22 but I think 21 is B
A good vector to genetically altered respiratory cells might be A VIRUS THAT HAS BEEN GENETICALLY ALTERED TO CARRY NORMAL HUMAN DNA.
Gene therapy is a medical method of treatment which uses genes to prevent or treat diseases. The method is used to correct the defects in genes which is causing a disease. In order to insert a normal gene to replace the defective one, a vector, which will carry the gene is needed. The vector that is usually used in this case is a virus, which has been doctored to carry a normal human DNA.
