单项选择题 The man stops to take his dog outside to do exercise because A．he doesn’t have enough time. B．he feels tired of running after his dog. C．he thinks his dog has mental problems. D．he treats the dog the way his parents treats him.

单项选择题 Lightning bugs can blink themselves because of a chemical substance A．in the head. B．in the tail. C．in the abdomen, D．in the wing.

单项选择题 The report issued by the Kaiser Family Foundation mainly shows that A．American kids have easy access to junk food. B．American kids are exposed to an attack of food ads. C．American kids do not take enough exercises. D．American kids’ fatness is likely due to watching too much TV.