Boeing has withdrawn a request for a safety exemption for a new version of its 737 Max jet that would have expedited its approval‚ raising questions over when the plane will enter service.  The US plane maker has come under mounting pressure to withdraw the request for the 737 Max 7 following the blowout of a section of the fuselage on an Alaska Airlines aircraft earlier this month. The incident‚ which involved the Max 9 model‚ has dealt a heavy blow to Boeing’s reputation and raised...