11.   The main difference is that commas are more formal than dashes.

12.   The main difference is that men do not blame themselves for their ambivalence toward parenthood.

13.   The main differences are the gauge and the number of extras that come with the machine.

14.   The other main difference between the two species is far more difficult to explain.

15.   What main differences are there between the northern and southern parts?

16.   The main difference between our brains and those of monkeys is that ours are bigger.

17.   What are the main differences and similarities between them?

18.   He skirted round his main differences with her.

19.   Describe the main differences in the budgeting process for a small retail firm and a large manufacturing firm.

20.   The main difference between the radical and Marxist positions revolves around the issue of medical power.