Question

Scientists believe that they have made a 1) __________ breakthrough in fighting HIV- they have shown what happens when an infection-fighting antibody attacks a 2) __________ in HIV's 3) __________ defences. Finding a vaccine against HIV has been very difficult because the proteins on the surface of the virus are continually mutating, but they have shown an antibody, called b12, attacking a weak spot of the virus where the protein is unstable. The virus is able to 4) __________ rapidly to avoid 5) __________ by the immune system, and is also covered in sugar molecules which block access by antibodies. 6) __________, certain parts of the virus must remain 7) __________ unchanged so that it can catch hold of and enter human cells. One protein that sticks out from the surface of the virus and binds to receptors on host cells is one such region, which makes it a target for vaccine development. 1) a) majority b) major c) solution d) final 2) a) gap b) space c) line d) shape 3) a) consider b) considerate c) considerably d) considerable 4) a) mutation b) mutant c)mutate d) mutating 5) a) detective b) detect c) detecting d) detection 6) a) Though b) However c) Also d) Even though 7) a) relatively

Answer 1

Answer:

Explanation: the answers lie in the given attachment

Answer 2

1. a)Major

2. a)gap

3. d)considerable

4. c)mutate

5. d)detection

6. b) However

7. a) relatively

Scientists believe that they have made a major breakthrough in fighting HIV- they have shown what happens when an infection-fighting antibody attacks a gap in HIV's considerable defences. Finding a vaccine against HIV has been very difficult because the proteins on the surface of the virus are continually mutating, but they have shown an antibody, called b12, attacking a weak spot of the virus where the protein is unstable. The virus is able to mutate rapidly to avoid detection by the immune system and is also covered in sugar molecules that block access by antibodies. However, certain parts of the virus must remain relatively unchanged so that it can catch hold of and enter human cells. One protein that sticks out from the surface of the virus and binds to receptors on host cells is one such region, which makes it a target for vaccine development.