He spends tow hours on his homework.He (spends ) two hours (doing ) his homework.3. It (takes )(him ) two hours (to )(do ) homework.4. (Doing) his homework (takes )(him ) two hours.你好! 本题不明白再问!其它题目请另外求助; 如果帮到你,请及时采纳,谢谢!