TOEFL Listening: TPO-TOEFL阅读TPO - O70BG454NQM0M1B5N$

According to paragraph 3, all of the following are ways in which the Savery and Newcomen engines were similar EXCEPT: A. Both became relatively inexpensive after the 1770s. B. Both produced steam by burning coal. C. Both were used to operate pumps. D. Both were very inefficient.