In order to make their schedules more standard, what did the railroads do?

Time Standardization: four continental time zones

Explanation:

In the 1880s when the transcontinental railroad was created by merging the Union Pacific and the Central Pacific Railroad, over 7,000 towns were using their own local across the United States and several thousand miles of rail tracks were by then in use to communicate USA and Canada, the company managers found out that the usage of local time was a serious drawback given that such local time zones created confusion and losses for the railroads. Because of this discrepancy the companies suggested and implemented four continental time zones solving in this way the issues of transporting passengers and cargo.

answer; ///i believe that the correct answer is refrigerants,(like r12) and aerosol

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.