Insect entombed in fossilised amber for tens of millions of years have provided the key to creating a new generation of antibiotic drugs that (ability) 1. could fight (fight) war on modern diseases. (1)

Research over the past two years 2. has uncovered (uncover) an antibiotic that 3. has been able to kill (ability)(kill) modern drug-resistant bacteria that 4. can cause (ability) (cause) potentially deadly diseases in humans. Present-day antibiotics 5. have nearly all been isolated (nearly all isolate) from micro-organisms that use them as a form of defence against their predators or competitors. But since the introduction of antibiotics into medicine 50 years ago, an alarming number 6.have become (become) ineffective because many bacteria 7.have developed (develop) resistance to the drugs. The antibiotics that 8.have been (be) in use millions of years ago 9.may have proven (probability) (prove) more deadly against drug-resistant modern strains of disease-causing bacteria. (2)

Raul Cano of California Polytechnic State University 10. said (say) the ancient antibiotics 11.had been (be) successful in fighting drug-resistant strains of staphyloccus bacteria, a 'superbug' that 12.has threatened (threaten) the health of patients in hospitals throughout the world. He now 13.intends (intend) to establish whether the antibiotics 14.might have (probability) (have) harmful side effects. (3)

A biotechnology company, Ambergene, 15.has been set up (set up) to develop the antibiotics into drugs. They hope that one ancient antibiotic molecule16. could be used (ability) (use) as a basis to synthesise a range of drugs. (4)

There17. have been (be) several attempts to extract material such as DNA from fossilised life-forms but many 18.were subsequently shown (subsequently show) to be contaminated. The fight against antibiotic-resistant strains of bacteria, such as tuberculosis and staphylococcus, therefore,19. could be helped (probability) (help) by the discovery. (5)

However, even the discovery of ancient antibiotics 20.may not halt (probability) (not halt) the rise of drug-resistant bacteria. Stuart Levy of Tufts University in Boston warned (warn) that the bacteria 21. would eventually evolve (eventually evolve) to fight back against the new drugs. "There 22.might also be (probability) (also be) an enzymeout there that 23.can degrade (ability) (degrade) it. So the only way to keep the life of that antibiotic going is to use it sensibly and not excessively," he said. (6)

Adapted from Prehistoric Insects Spawn New Drugs by Steve Connor, printed in Insight into IELTS. 1999. Cambridge University Press.