更多"By the 1820’s in the United States,"的相关试题:
[单项选择]By the 1820’s in the United States, when steamboats were common on western waters, these boats were mostly powered by engines built in the West (Pittsburgh, Cincinnati, or Louisville), and of a distinctive western design specially suited to western needs. The first steam engines (21) practical use in England and the United States were (22) low-pressure design. This was the type first (23) by James Watt, then manufactured by the firm of Boulton and Watt. Steam was (24) in a large, double-acting vertical cylinder, but the steam reached only a few pounds of pressure per square inch. It was low-pressure engines of this type that (25) first introduced into the United States by Robert Fulton. He (26) such a Boulton and Watt engine from England to run the Clermont. But this type of engine was ,expensive and complicated, (27) many precision-fitted moving parts.
The engine that became standard on western steamboats was of a dif
A. on
B. by
C. for
D. in
