You mean it's necesary to take a taxi.还是You mean it necesary to take a taxi,哪种说法对

You mean it's necesary to take a taxi.还是You mean it necesary to take a taxi,哪种说法对

You mean it necesary to take a taxi.这种,因为it后是形式宾语,形式宾语的结构是
主语+谓语+it+形容词+to do/ doing/that从句.