Which one is more acceptable?
1. Each boy and each girl has done his duty.
2. Each boy and each girl has done his or her duty.
3. Each boy and each girl has done their duty.
Edit: Here is what I think.
I think (1) isn't acceptable because 'his' is in masculine gender, which doesn't fit the noun 'girl'. (3) isn't acceptable because the verb 'has' is singular but the pronoun 'their' is plural. (2) is ok but the expression "his or her" looks awkward.