I'll say the answer is D, or 4, since the Aztecs did expand over the warm tropical lowlands and the cool tropical highlands which would allow them to have more options in terms of which kinds of crops could be grown.
Answer:
The past continuous is formed from the past tense of "to be" with the base of the main verb plus the ending "-ing" from the verb.
Some examples
• The sun was shining every day that summer.
• At 6 o'clock, I was eating dinner.
• At noon, he was arriving.
There is no question here. do you want it explained? If so, there is no score if you do not swing the bat. basically, always try your best.