He considered studying medicine but fainted ____________ blood, so he switched to civil engineering.
A. at the sound of
B. at the thought of
C. at the sight of
D. at the smell of
The exhibition has been held ______________ World Press Freedom Day annual celebration.
A. on the occasion of
B. on occasion
C. on every occasion
D. on rare occasions
During wintertime, snow may fall in southern China _______________ .
A. on the occasion of
B. on occasion
C. on every occasion
D. on rare occasions
If you are a Chinese, your stomach may turn ____________ cheese — a food normally accepted in many Western countries.
A. at the sound of
B. at the thought of
C. at the sight of
D. at the smell of