TEXT B
We recognize visual form only by means of light, we recognize the existence of light only by means of form, and we further recognize that color is an effect of light in relation to form and its inherent texture. In nature, light creates color; in painting, color creates light.
　
In symphonic painting, color is the real building medium. "When color is richest, form is fullest." This declaration of Cézanne's is a guide for painters.
　
Swinging and pulsating from and its counterpart, resonating space, originate in color intervals. In a color interval, the finest differentiations of color function as powerful contrasts. A color interval is comparable to the tension created by a form relation. What a tension signifies in regard to form, an interval signifies in regard to color; it is a tension between colors that makes color a plastic means.
　
A painting must have form and light unity. It must light up from the inside through the intrinsic qualities which color relations offer. It must not be illuminated from the outside by superficial effects. When it lights up from the inside, the painted surface breathes, because the interval relations which dominate the whole cause it to oscillate and to vibrate.
　
A painted surface must retain the transparency of a jewel which stands as a prototype of exactly ordered form, on the one hand, and as a prototype of the highest light emanation on the other.
　
The Impressionists led painting back to the two-dimensionality in the picture through the creation of a light unity, whereas their attempt to create atmosphere and spatial effectiveness by means of color, resulted in the impregnation of their works with the quality of translucence which became synonymous with the transparency of the picture plane.
　
Light must not be conceived as illumination -- it forces into the picture through color development. Illumination is superficial. Light must be created. In this matter alone is the balance of light possible.
　
The formation of a light unity becomes identified with the two-dimensionality of the picture. Such a formation is based on comprehension light complexities. Color unity, in the same matter, is identified with the two-dimensionality of the picture.
　
It results from color tensions created by color intervals. Thus the end product of all color intervals is two-dimensionality.
　
Spatial and formal unity and light and color unity create the plastic two-dimensionality of the picture.
　
Since light is best expressed through differences in color quality, color should not be handled as a tonal gradation, to produce the effect of light.
　
The psychological expression of color lies in unexpected relations and associations.

39. What would be an appropriate title for this selection?
A. On Light and Color
B. The Expression of Color and Light by Impressionists
C. Visual Effects in Painting
D. The Formation of a Light Unity and a Color Unity
正确答案是

40. What does the writer mean by form and light unity?
A. A painting is lit up from the outside.
B. A painting lights up through the qualities that color relations offer.
C. The painting's surface breathe and vibrate
D. The interval color relations dominate the painting.
正确答案是

41. What cause the plastic two-dimensionality of a picture?
A. Unexpected relations and associations.
B. Spatial and formal unity.
C. Light and color unity.
D. B and C.
正确答案是