题目

It is reported that using a smartphone at mealtimes can lead to an expanding waistline. Researchers have found that men and women consumed 15 percent more calories when looking at their phones while eating. They also ate more fatty food. The groundbreaking study suggests that staring at a phone screen may distract diners from how much food they are actually eating.It may prevent the correct understanding of the brain over the amount of food that is eaten, said researchers who filmed 62 volunteers eating alone.The men and women, aged from 18 to 28, were invited to help themselves to a choice of如图，AD//BC，BD平分∠ABC，∠A ：∠ABC=2：1，则∠ADB=         °