阅读下列句子，在空白处填入1个适当的单词或括号内单词的正确形式。
1. He experimented with different styles of painting, but was most famous for his work in Cubism, which often uses acute angles and ______ the world is represented as being constructed of cubes and rectangles.
2. By popular consensus, this is the most valuable painting in the world—it is impossible to calculate what price it would fetch if it ever ______ (come) on the market.
3. Unfortunately, although van Gogh committed his whole being to painting, he received little reward ______ his effort.
4. As a teenager, he began painting scenes of local fishermen and sailors along the canals in Suzhou, ______ sold these paintings to tourists and passers-by as souvenirs.
5. We can use old pieces of cloth as brushes, or wrinkle the cloth together to ______（form） an interesting pattern.
6. That is, the main criterion for ______（include）is that the film must not be financed by Hollywood studios.
7. It was then that Robert Redford became its sponsor and changed the focus to independent films, often ______（make） on very modest budgets.
8. ______ on such a trip can you gain a better appreciation of European art.