My uncle brought his girlfriend to ____ my parents’ happy marriage with her own eyes at Christmas that year.

One of the consequences of our planet's being warming up is a（n）_______ in the number of natural disasters. 

The great _______ of my plan is that it’s so cheap compared to the others.

I didn’t know it could do terrible ______to your heart and lungs or ______was more difficult for smoking couples to become pregnant.

I broke my relationship with John because he always found _____ with me.