用at birth翻译

问题描述:

用at birth翻译
我出生时有三公斤重
我的翻译:
①I was 1 kilogram when I was at birth.
②I was 1 kilogram when I at birth.
③I was 1 kilogram at birth.
那个对?请解释一下.
at birth前要加be动词吗?

第三句是对的,at birth前不加be,要熟记
祝楼主更上一层楼