That's just as it should be.; That's only natural. 理所当然。
You can certainly use my dictionary. 你当然可以用我的字典了。
It goes without saying that we should help a comrade in difficulty. 同志有困难当然要帮助。
natural ally 当然同盟军
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)