My friend's weight is 55 kg.(句意相同) My friend _____ 55 kg.My friend _____ 55 kg.

My friend's weight is 55 kg.(句意相同) My friend _____ 55 kg.My friend _____ 55 kg.

weighs(这里作动词使用哦!)
is (这里就是be动词直接接后面的数量名词作表语啦,不过前面是my friend,所以be动词也相应地用单数形式is哈!)

weighs

weighs 动词 重量为，称重

My friend _weights____ 55 kg.
欢迎追问哦
是名词变成动词

weights
is

is weights