Question

stephen hawking made important discoveries about black holes. he was one of the most respected scientists of his time.
joining words
because though before
① combine the sentences into one sentence. use one of the joining words.

Explanation:

Se une las dos oraciones usando la conjunción "because", ya que esta indica la causa por la que Stephen Hawking fue uno de los científicos más respetados de su época: sus descubrimientos sobre agujeros negros.

Answer:

Stephen Hawking was one of the most respected scientists of his time because he made important discoveries about black holes.