[填空题]
Estimate the time betweenzfbr1k*:s et0;q (t-e)kk okm each photofl( cetf .bjg,.nou6i n7ash of the apple in Fig. 2–18 (or number of photoflashes per second). Assume the apple is about 10 cm in diameter. [Hint: Use two apple positions, but nogicj(f ,nn.bo.t e6u7 t the unclear ones at the top.]
T = s
flashes per second