Mary noticed Amy's accent so 
OPTIONS:
- Mary asked her which country she had been a citizen of.
- Amy asked her which country she had been a citizen of.
Mary asked her which country she had been a citizen of.

Monica is more concerned about the effects of radiation than Mary because 
OPTIONS:
- Monica works at a nuclear power facility.
- Mary works at a nuclear power facility.
Monica works at a nuclear power facility.

The fountain pen can not write smoothly on the paper because the 
OPTIONS:
- paper is too sharp.
- fountain pen is too sharp.
fountain pen is too sharp.