1 . Intelligence, diligence and persistence are the three main factors c__________ to students’ outstanding performance. (根据首字母单词拼写)

2 . Props also c________ to a film’s success. （根据首字母单词拼写）

3 . From this story, I am firmly convinced of the significance of honesty, which will c_____ to building a warm and harmonious society.

4 . Most of the European countries didn't attach importance to the coVID-19 last year, c _____ to its outbreak across the world. （根据首字母填空）