Question

most bodies of water in antarctica are frozen.
deep lake is too salty to completely freeze.
however therefore ← joining words
rewrite the sentences, and use one of the joining words in the correct place. your final response should be two sentences.

Explanation:

The first sentence states most Antarctic water bodies are frozen, and the second presents an exception (Deep Lake not freezing due to salinity). "However" is used to show contrast between the general case and the exception. So we rewrite using "however" to connect the contrasting ideas.

Answer:

Most bodies of water in Antarctica are frozen. However, Deep Lake is too salty to completely freeze.