Theindexwasunder6550inearlyMarch,dotheadvancehasbeen35%sincethen...这是一种什么语法dotheadvancehasbeen35%sincethen...这一部分是疑点,

Question

The index was under 6550 in early March ,do the advance has been 35% since then...这是一种什么语法
do the advance has been 35% since then...这一部分是疑点,

Answer 1

do 或是 though （即 although）打错的.
The index was under 6550 in early March, though the advance has been 35% since then.
该指数三月初低于 6550,但自那时以来已升值 35%.