 Complete the following phrase:  By the late 1960s, the Nordschleife and many other tracks were becoming increasingly dangerous for the latest generation of F1 cars. In 1967, a chicane was added before the startfinish straight, called Hohenrain, in order to reduce speeds at the pit lane entry. This made the track longer. Even this change, however, was not enough to keep Stewart from nicknaming it The Green Hell  following his victory in the 