23. Поставить глагол have в нужную форму (have, has, had, will have):
1. The zone immediately around the mold was clear, as if the mold (had) secreted something that inhibited bacterial growth. 2. Nowadays vaccinations and antibiotics, plus even more importantly clean water, (have) lowered our concern over infectious organisms. 3. Immunizations (have) already decreased the risk of some frightening diseases but others, such as Ebola and the Zika virus, remind us that we must be alert. 4. There are many different ways in which scientists (have) classified the millions of microbes in our environment. 5. Recent improvements in technology (have) provided new and amazing insights into the dynamic structure of this single cell organism. 6. We believe that scientists (have) used their knowledge of microbes to get biotechnologically important enzymes by 2025. 7. But it was not until 1854, when it was proved that an epidemic of cholera (have) had its origin in polluted water.