.Most animals and plants are sensitive _______ sudden changes in temperature.
There are three girls in the room, ________ is Tom's sister.
I'll never forget the day _______ I bought my own guitar with my own money.
She is just the girl, with _______ my brother came to visit me last month.
Last night we saw two movies, _______ was interesting.
This is the house in _______ I was born thirty years ago.