阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

In an effort to fight against global warming, Purdue University engineers have created the whitest paint that can keep surfaces cooler than the formulation(配方)that the researchers had 【小题1】 (previous) shown.

The new whitest paint formulation reflects up to 98. 1% of sunlight compared with the 95. 5% of sunlight 【小题2】 (reflect) by the researchers' previous white paint and sends heat away from a surface at 【小题3】 same time.

Two features give the paint its extreme whiteness. One is the 【小题4】 (paint) high concentration of a special chemical, 【小题5】 is used to make photo paper white as well. And the second feature is that the barium sulfate particles(硫酸钡粒子) are all different 【小题6】 size in the paint. How much each particle scatters(散射) light 【小题7】 (depend) on its size, so a wider range of particle sizes allows the paint to scatter more of the light from the sun.

The extreme whiteness also means that the paint is the 【小题8】 (cool) on record. Using high-accuracy temperature reading equipment, the researchers have shown that the paint can keep surfaces 19℉ cooler than their surroundings at night and cool surfaces 8 ℉ below their surroundings under strong sunlight during noon hours, The researchers hold a firm 【小题9】 (believe) that coating buildings with this paint will one day cool them off enough 【小题10】(reduce) the need for air conditioning.