Questions & Answers about Ветрозащитная куртка и гамаши уже готовы.
In Russian, the verb to be is usually omitted in the present tense.
So:
- Ветрозащитная куртка и гамаши уже готовы.
- literally: Windproof jacket and gaiters already ready.
English needs are, but Russian normally does not:
- Я дома. = I am at home.
- Она врач. = She is a doctor.
If the sentence were in the past or future, Russian would use a form of быть:
- ... были готовы = ... were ready
- ... будут готовы = ... will be ready
Because the subject is two things together:
- ветрозащитная куртка
- гамаши
They are joined by и (and), so the whole subject is plural. That means the predicate must also be plural:
- куртка ... готова = the jacket is ready
- гамаши ... готовы = the gaiters are ready
- куртка и гамаши ... готовы = the jacket and the gaiters are ready
So готовы agrees with the whole compound subject.