Final answer:
A complex sentence version of the given statement could be, 'Although Kalla is a large and strong dog, she would never hurt anyone.'
Step-by-step explanation:
To rewrite the sentence 'Kalla is a large, strong dog, but she would never hurt anyone' as a complex sentence, you can use a subordinate clause to add depth and detail. Here is one possible complex sentence: 'Although Kalla is a large and strong dog, she would never hurt anyone.'
In this version, the clause beginning with 'although' functions as the subordinate clause, providing a contrast to the main clause, which states that Kalla would never hurt anyone.