答案保证正确!

1. happily
副词happily修饰动词短语look at
2. happy
形容词happy放在系动词looks后面,做表语,构成系表结构.
而副词一般不能做表语



如果对你有所帮助,请点击本页面中的“选为满意回答”按钮,谢谢!没有at呀！后面有at啊第一题其实是出题人故意诱惑你，looks happily at his mum 其实是：looks at his mum happily