3. They (to announce) our flight. We (to have) a problem, One of our suitcases (to miss).
Какое время ставить и почему? Выбор из Present Simple Present Progressive Past Simple Past Progressive.
Именно почему. поставить я и сам могу :C

Ответ:

They are announcing our flight. (Сейчас происходит длительное действие). We have a problem. One of our suitcases is missing. Лучше – is missed

Объяснение:

Часто  в интернете можно увидеть фразу  - Houston, we have a problem

"I am having a problem" is used when speaking of an interpersonal matter, and "I have a problem" when referring to some other type of situation such as a problem with a mechanical device. Actually, they're pretty much interchangeable, but that's a personal preference I have in usage, since "I am having a problem" denotes something within me is having a difficulty about another person, which doesn't imply it's the other's fault, where "I have a problem" tends to imply the fault is outside me personally, as in a malfunctioning device.