单项选择题
A．locate the problem areas B．drew a color-coded map C．measure the size of the affected area D．estimate the damage to the crops
A．sprayed with pesticides B．in pour physical condition C．facing an infrared scanner D．exposed to excessive sun rays
A．transforming poisoned rain B．consulting infrared scanning experts C．resorting to spot-spraying D．detecting crop problems at an early date