I left out the following sentences. Thank you very much.

1)His sallow skin enables one to see the pulsing work of his muscles, veins and arteries. Victor dreams of Elizabeth (but he dreams about Elizabeth walking in Ingolstadt).
2) Victor is closed in his laboratory with human body parts. The protagonist enters slowly in (??) the old man’s room. The narrator not only (?) kills the old man but he buries him in the floor.
3)The narrator is able (better “seems/pretends”) to hear the beating of the old man’s heart. The narrator is obsessed with (can you use “by”) the old man’s eye, which is like that of a vulture.
4) He is horrified of/by (are they both possible?) his creation.

1)His sallow skin enables one to visualize the pulsing work of his muscles, veins, and arteries. Victor dreams of Elizabeth, walking in Ingolstadt.

2) Victor is closed in his laboratory with human body parts. The protagonist slowly enters the old man’s room. The narrator not only kills the old man, but he also buries him in the floor.

3)The narrator seems to hear the beating of the old man’s heart. The narrator is obsessed with the old man’s eye, which is like that of a vulture.

4) He is horrified by his creation.