in the 18th century和in 18th century有区别吗?
一篇英语阅读里面第一句：when tea and coffee were first introduced to Europe in the 18th century，第一个问题是tea and coffee were first introduced to Europe in______A______
A 19th century
B 18th century
C in 1801
D 1921
只有in the 18th century=in 19th century时才能选择A啊
难道in the 18th century和in 19th century指的都是1801~1900？
那in 18th century指的就是1701~1800？