Put S for Subordinate Clauses, and I for Independent Clauses.
1. We had an enjoyable weekend when we spent two days on Lloyd's farm.
We had an enjoyable weekend is underlined
2. Before the sun came up, we had eaten a huge breakfast.
Before the sun came up is underlined
3. Jeremy helped milk several cows, and Tamara spread grain for the chickens.
Tamara spread grain for the chickens is underlined
4. I slowly drove the tractor to the barn, but Steven attached the tractor's trailer.
Steven attached the tractor's trailer is underlined
5. After we loaded the trailer with bales of hay, we hauled the load into the pasture.
After we loaded the trailer with bales of hay is underlined
6. I wasn't afraid of the cows until one of them lumbered toward me.
until one of them lumbered toward me is underline