Question

we were going to mexico for a long vacation. past progressive present progressive future progressive

Explanation:

The sentence "We were going to Mexico for a long vacation" uses the structure "was/were + present participle" (here "were going"), which is the form of the past progressive tense. The present progressive uses "am/is/are + present participle", and future progressive uses "will be + present participle", so this sentence is in the past progressive.

Answer:

past progressive