Question: What's the HC for the standard with NO x of 7.0 g/kWh?
Schema: create table table_2780146_6 (hc__g_kwh_ varchar, no_x__g_kwh_ varchar, PRIMARY KEY (hc__g_kwh_))
SQL: select hc__g_kwh_ from table_2780146_6 where no_x__g_kwh_ = "7.0"