The last sentence of the first paragraph most probably implies that it is ______.

单项选择题Some people do not openly admit they have ambition because ______.

单项选择题It is generally believed that ambition may be well regarded if ______.

单项选择题From the last paragraph the conclusion can be drawn that ambition should be maintained ______.

单项选择题The writer thinks that the popular version of the wagon train is ______.

单项选择题According to this passage, the nineteenth century seems to be an age of ______.