inventions of ancient china ⅰ.单词拼写 1．the relationship between teachers and students is ______(平等的)． 2．walking helps to reduce ________(压力) and calm your emotions. 3．everyone should make a ________(贡献) to protecting the environment. 4．he ________(辞职) his post because he had been offered a better job. 5．jack never did something that went against his ________(原则)． 6．only after a long ________(争论) did he agree with us. 7．we must carry on till success in spite of the extremely difficult ________(条件)．
