Answer:
The sentences that do not have a gerund are:
C. She was dancing with her best friend.
D. After school gets out, I will be swimming most of the summer.
Step-by-step explanation:
A gerund is a verb ending in -ing that functions as a noun. Because a gerund acts like a noun, it can be a subject complement -like sentence A-, an object -like sentence B-, a subject -like sentence E- or part of a compound noun -like sentence F.
In sentences C and D, the verbs with -ing are acting as main verbs rather than as nouns.