1. Many folk cures || which have been around for centuries || may be more therapeutic || than previously suspected. 2. A case in point is that of penicillin. Alexander Fleming || did not just randomly choose cheese molds to study || when he discovered this very important bacteria-killing substance. 3. Moldy cheese || was frequently given to patients as a remedy for illness || at one time. 4. Fleming || just isolated what it was about the cheese || which cured the patients. 5. In parts of South America, || a powder || obtained from grinding of sugar cane, || is used for healing infections in wounds and ulcers. 6. This usage || may date back to pre-Colombian times. 7. Experiments carried out on several hundred patients || indicate, || that ordinary sugar in high concentrations || is lethal to bacteria. 8. Its suction effect || eliminates dead cells, || and it generates a glasslike layer which || protects the wound and ensures healing. 9. Another example of folk medicine || which scientists are investigating is that || of Arab fishermen who rub their wounds with a venomous catfish || to quicken healing. 10. This catfish || excretes a gel-like slime || which scientists have found to contain antibiotics, || a coagulant that helps close injured blood vessels, || anti-inflammatory agents, || and a chemical that directs production of a glue-like material || that aids healing. 11. It is hoped that || by documenting these folk remedies || and experimenting to see if results are indeed beneficial, || an analysis of the substances can be made, and synthetic substances || can be developed for human consumption.

Синтагма - совокупность нескольких слов, объединённых по принципу семантико-грамматически-фонетической сочетаемости, относительно законченный по смыслу отрезок речевой цепи.
Ассимиляция согласных - соответствие звонкости/глухости, для двух идущих рядом согласных (звонких либо глухих).

Почему в английском тексте запятые факультативны, а в русском они обязательны?

В английском языке структура предложения фиксирована (расположение подлежащего, сказуемого и т.д.), поэтому запятые не являются обязательными к использованию.
В русском языке существует возможность “маневра” по структуре предложения, поэтому использование запятых является обязательным.

Что такое ассимиляция согласных и какую роль с т.з. (= точки зрения) смыслоразличения она выполняет?

Ассимиляция позволяет разделить предложение на смысловые блоки, каждый из которых произносится “слитно”, образуя паузы м/у этими блоками.

3. Moldy cheese was frequently given to patients || as a remedy for illness || at one time.

5. In parts of South America, || a powder obtained from grinding of sugar cane, || is used for healing infections in wounds || and ulcers.

7. Experiments carried out on several hundred patients || indicate, that ordinary sugar in high concentrations || is lethal to bacteria.

8. Its suction effect eliminates dead cells, || and it generates a glasslike layer which protects the wound || and ensures healing.

9. Another example of folk medicine which scientists are investigating || is that of Arab fishermen who rub their wounds with a venomous catfish || to quicken healing.

10. This catfish excretes a gel-like slime which scientists have found || to contain antibiotics, || a coagulant that helps close injured blood vessels, || anti-inflammatory agents, || and a chemical that directs production of a glue-like material that aids healing.

11. It is hoped that by documenting these folk remedies || and experimenting to see if results are indeed beneficial, || an analysis of the substances can be made, || and synthetic substances can be developed for human consumption.

very important / close injured - а где здесь ассимиляция?

здесь нет ассимиляции

А здесь есть ассимиляция: it was?

между звуками t и w

Да, здесь есть ассимиляция.

здесь нет ассимиляции

между гласными может быть ассимиляция = гласные ассимилируют?