Scientists photographed for the first time ever _____ wild gorillas used a stick to test the depth of a pool before getting into it, according to a recent study.
English is a language shared by several diverse cultures, each of __________ uses it somewhat differently.
Many young people in the West are expected to leave __________ could be life's most important decision—marriage—almost entirely up to luck.
My chest __________ when I make a deep breath, doctor.
The plane, __________ by another plane, broke into pieces.
It worries me the way he keeps __________ his mind.