Which of the following best expresses the main idea of the passage?
（A）Trains helped pioneers to cross the Rocky Mountains.
（B） Railroad played an important role in American history.
（C） Trains controlled American economy in the 19th century.
（D） Railroads grew rapidly between 1865 and 1900.
参考答案
继续答题：下一题
更多大学英语单项选择题库试题
- 1— I will come to attend your lecture at 10:00 tomorrow.-考察时态 — I'm sorry, by then my lecture will have ended and I ____ my guests in my office.
- 2Here’s my card, Let’s keep in ___.
- 3I confess it wasn’t until my _____ twenties that I found my true path in life.
- 4I’ve never seen droughts on such a large ____________
- 5They had a (n) _____argument for several hours without reaching an agreement.
