Question

however, when the rocky mountain locusts left in the mid - 1870s, they never returned. by the turn of the century, they had mysteriously become extinct, leaving everyone wondering what happened.
complete the sentences to create a summary of the passage.
in the 1870s, western farmers suffered from devastating. many families. but by the end of the century, the problem totally disappeared, and nobody.

Explanation:

The passage mentions Rocky Mountain locusts. In the 1870s, locusts (which are insects) would cause problems for farmers (devastating locust swarms). Families would be affected (had to leave). And when they became extinct, no one knew the reason (knew why).

Answer:

In the 1870s, western farmers suffered from devastating locust swarms. Many families had to leave. But by the end of the century, the problem totally disappeared, and nobody knew why.