A 这是一个强调句的疑问形式
选A后 还原成陈述语序是 it was in the 1870s that Marx stared to learn russian.这是对时间状语in the 1870s的强调
其实就是 Marx stared to learn russian in the 1870s
A 这是一个强调句的疑问形式
选A后 还原成陈述语序是 it was in the 1870s that Marx stared to learn russian.这是对时间状语in the 1870s的强调
其实就是 Marx stared to learn russian in the 1870s