Lightning bugs can blink themselves because of a chemical substance
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.

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.

A．it couldn’t connect to the Internet.
B．it crashed repeatedly in some cases.
C．its modem was broken.
D．its screen didn’t function well.