A、Because they are physically ill. B、Because there is something wrong with their nerve. C、The reasons are unknown. D、Because the

We continue the first in a new series of reports from time to time on raising children. Today we discuss some ways to help bed-wetters stay dry all night long.
    Researchers say the young people who do it are usually physically and emotionally normal. They say the causes of bed-wetting are not known. But they think most cases probably result from a mix of things including slower physical development. Often there is a strong family history of bed-wetting.
    The good news is that most children grow out of it over time. So, until that happens, here are some steps that might help.
    First, consider a limit on the amount of liquid a child drinks before bedtime. Also, make sure children use the bathroom right before bed—an empty bladder at bedtime should help.
    Some parents wake their children at night to use the bathroom. Others set a timer to sound, so children wake up on their own.
    The Mayo Clinic says even going to bed 30 minutes earlier can help some children stop wetting the bed.
    Some parents put a plastic cover on the bed, then a cloth sheet, followed by an additional set of plastic and cloth sheets. This way, it is easy to remove wet coverings and have a dry set ready.
    Doctors say the first thing a parent should do about bed-wetting is talk to their child’s doctor. When nothing else works, doctors sometimes give medicines to reduce urine production, or antidepressant drugs or both.