сложноподчинённые предложения

[Natalia]

"Doctors would write a prescription for a medication that needed to be made from scratch." - это НЕ сложноподчинённое предложения, правильно?
"The pharmacist needed to know how to compound these chemicals and extracts into various dosage forms like capsules, tablets and suspensions." - и это тоже не сложноподчинённое, так?
"Foxglove’s activity was determined by finding how much was needed to kill a cat.
Chrysanthemum’s activity was found by seeing how many flies were killed over period of time by being exposed to the extract.
Once activity was established the medication would be compounded into a form the doctor prescribed often tinctures." - это сложноподчинённые, как я думаю.
Очень буду признательна за быстрый ответ, потому что я увязла в этой теме completely. Please, help!

[English Guru]

"Doctors would write a prescription for a medication that needed to be made from scratch." - это НЕ сложноподчинённое предложения, правильно?

лекарство, которое .... Вполне себе сложноподчиненное предложение!

"The pharmacist needed to know how to compound these chemicals and extracts into various dosage forms like capsules, tablets and suspensions." - и это тоже не сложноподчинённое, так?

Да, правильно.

Once activity was established the medication would be compounded into a form the doctor prescribed often tinctures." - это сложноподчинённые, как я думаю.

Строго говоря, это предложение сложное бессоюзное, а не сложноподчиненное

[Natalia]

Dear Guru! I do not understand your comment. It only makes my situation worse. I mean thank you very much, but it doesn't give me a clue, the rule to distinguish on my own clearly when it is complex sentence and when it is not. Moreover, I have read your article (with a table) about the complex sentences on this site and there is no such an examples with dependent clause like "that needed to be made from scratch". I have read thousand articles since last Monday about complex sentences and all give examples and explanations with a subject and a verb in every clause in the complex sentences. So, about this sentence with doctors, there is no subject in "that needed to be made from scratch" Or "that" it is a subject, but here it is rather conjunction, - который, not pronoun - тот самый, этот.

"The pharmacist needed to know how to compound these chemicals and extracts into various dosage forms like capsules, tablets and suspensions." - why do you agree with me about this sentence and think it isn't complex, I wonder?

As for the last example you define for me. Your answer again creates doubts instead of clarity in my mind. I think it is a conditional sentence and this kind of a sentence definitely relate to complex sentences. The point is the first part connected with second by conditions - as only... then it became possible. So, please clarify the rule by which you decide it is a compound sentence instead of thinking it is complex. Please, please make it clear!!!

[Natalia]

Dear Guru, you are wrong. Now I am quite sure about it.
Уважаемый Гуру, вы ошибаетесь. Теперь я вполне уверена в этом.
This sentence about doctors, which you have defined as a complex, isn't complex.
Это предложение о докторах, которое Вы определили как сложноподчинённое, вовсе не сложноподчинённое.
("Doctors would write a prescription for a medication that needed to be made from scratch").
It isn't point how it will be looking translated in Russian.
Дело не в том, как оно будет выглядеть переведенное на английский.
The point is that this sentence isn't complex in English because the relative clause ("that needed to be made from scratch") doesn't contain its own subject and verb. This is a main feature to distinguish a complex sentence from any other.
Дело в том, что это предложение не является сложноподчинённым на английском потому, что эта часть предложения ("that needed to be made from scratch" = которое нужно было сделать с нуля) не содержит его собственного субъекта и глагола. Это является главной четой, чтобы отличить сложноподчинённое предложение от других.
I mean every clause must have its own subject and verb. Я имею в виду, что и главное предложение и зависимые (придаточные) должны иметь свой собственный субъект и глагол.

As for the last sentence, you have defined as the compound without a conjunction ("Once activity was established the medication would be compounded into a form the doctor prescribed often tinctures."), you are wrong again.
Что касается последнего предложения, которое Вы определили как сложное бессоюзное ("Once activity was established the medication would be compounded into a form the doctor prescribed often tinctures." = Как только активность была установлена, лекарство составляли в предписанной врачом форме, часто в настойках.), Вы ошибаетесь снова.

"Once" here means "as soon as" or "from the moment when". It is a conjunction which is introducing a condition. Inasmuch as conditional sentences are complex, this sentence is complex.
"Once" означает здесь "Как только" или " С того момента когда". Это союз, который выражает условие. Поскольку условные предложения являются сложноподчинёнными, это предложение сложноподчинённое.

Nonetheless, I wonder about your way of thinking. Once again, I ask you explain how you understand this subject (this is a complex sentence, by the way = a subject and a verb is in every clauses).
Тем не менее, мне интересен Ваш путь размышления. Еще раз я прошу Вас объяснить, как Вы понимаете эту тему.

("This sentence about doctors, which you have defined as a complex, isn't complex." - Это сложноподчинённое предложение, кстати говоря = субъект и глагол есть и в главном предложении и в придаточном.)