But the force of geographic conditions peculiar to America, the interplay of the varied national groups upon one another, and the sheer difficulty of maintaining old-world ways in a raw, new continent caused significant changes.
在这个句子中,一共有几个主语?
A、 1
B、 2
C、 3
D、 4
But the force of geographic conditions peculiar to America, - Unit 6 LBT Analysis(LBT长难句分析) - 英语语法与句子写作 - U校园 | 大学网课搜题引擎