Which sentence contains a singular subject? both jerry and his sister attended the meeting. several in the audience gave the actors a standing ovation. the deer entered the forest at the same place they had come out. any of those ideas sounds good to me.

The greatest gift the sumerians gave the world was the invention of writing. the sumerians were a wealthy people. they needed some way to keep track of what they owned. they began drawing pictures. they used a reed as a pen. they drew on soft pieces of clay. the soft clay was then dried in the sun. the tablet became a permanent record. later, the sumerian drawings changed into wedge-shaped symbols. this kind of writing is called cuneiform. by putting symbols together, the sumerians could write entire sentences.