1 . 判断下列句子中so that引导的是什么从句
1. Speak clearly so that they can understand you. ________
2. He spoke clearly so that they understood him. ________

2 . 他辞去了工作，以便安享晚年。
① He resigned his post   _________ _________   he could enjoy his old age.(目的状语从句)
② He resigned his post   _________ _________ _________   he could enjoy his old age.(目的状语从句)
③ He resigned his post   _________ _________ _________   enjoy his old age.(简单句)
④ He resigned his post   _________ _________ _________     enjoy his old age.(简单句)