Because of his tender age and incomplete understanding of the need to position the key just so, he would usually fail.

由于他还年幼，不太明白得把钥匙放准位置才成，因此总塞不进去。

youdao

Because of his tender age and incomplete understanding of the need to position the key just so, he would usually fail.

由于他还年幼，不太明白得把钥匙放准位置才成，因此总塞不进去。

youdao