The car was stuck in the snow

Add a subordinating conjunction and

continue the complex sentence.

The car was stuck in the snow as a result of snow that falls the whole night.

Explanation:

The complex sentence must have an independent and dependent clause. The independent clause must contain subordinating conjunction or a relative pronoun.

In an example, the independent clause has a subordinating conjunction "as a result of". The two sentences are connected with a subordinating conjunction. The consequence of snow falling is a car who is stuck in the snow and these two actions are connected in a complex sentence.