On his back with that

Question

On his back with that wonderful hot sun on his face, he knew he could only see in his mind’s eye the smile on his mother’s face.这一句的前半句是什么成分？

Answer 1

On his back with that wonderful hot sun on his face躺在他的背上，脸上晒着灿烂的阳光。
是伴随状语。

Answer 2

前部分是状语从句。

Answer 3

On his back with that wonderful hot sun on his face, he knew he could only see in his mind’s eye the smile on his mother’s face.
这一句的前半句On his back with that wonderful hot sun on his face是状语, 地点状语.
背上，脸上烤着那灿烂火热太阳，他知道,自己只能从脑中看到母亲脸上的笑容。