Why was the following sentence written in passive voice? “the liquids were combined at a temperature of 150 degrees celsius.”

The verb is the most important part of the sentence.

marriage difficulties adversely affect parent-child communication

dr. kings dream speech

explanation:

it was late in the day and hot, and after a long march and an afternoon of speeches about federal legislation, unemployment and racial and social justice, the rev. dr. martin luther king jr. finally stepped to the lectern, in front of the lincoln memorial, to address the crowd of 250,000 gathered on the national mall.