All the questions I have posted recently come from a book called The Ultimate Guide to SAT Grammar by Erica L. Meltzer. It seems like there are some typos and errors in this book. Thank you for your help!
I can help with some examples of some subjects joined by and that are considered as one thing. Brown bread and butter is usually eaten with smoked salmon. Whisky and soda is his favourite drink. The stitching and binding of books is done on this machine.