2. HE HAD VERY BAD HEALTH. HE LIVES VERY CAREFULLY. IT IS INEXPLICABLE TO THE DOCTOR. THE DOCTOR HAS ATTENDED HIM FOR YEARS. HE TOLD ME THIS

The question is incomplete and the full version can be found online.

He told me that the doctor that has attended him for years can´t explain why he has very bad health even though he lives very carefully.

Explanation:

The question requires combining the set of Simple sentences into one Complex sentence.

A complex sentence contains an independent clause (one that can stand alone as a sentence) and at least one dependent clause, which cannot stand alone despite having a subject and a verb. The clauses, then, are not equal, and there has to be a coordinating conjunction that establishes the rank of one or more of the clauses to make them less equal.

In this example, the coordinating conjunctions used are "that" and "even though."