Final answer:
The sentences are joined by using the conjunctions 'although', 'and', and 'that' to cogently combine the ideas into single coherent sentences.
Step-by-step explanation:
The student is asking how to use conjunctions to join pairs of sentences. Here are the revised sentences using conjunctions:
- Although he has never ended school, he possesses a lot of wisdom.
- He waited for them, and they came sixth.
- It is certain that he will be late.
The original pairs of sentences are combined using the conjunctions 'although', 'and', and 'that' to create a smoother, coherent expression of the ideas previously presented in two separate sentences.