4、Watching a child struggle to breathe during as asthma (哮喘) attack is frightening for any parent. So it is only natural that most moms and dads will try just about anything, including spending a lot of money to keep an attack at bay. Trouble is, more than half of parents are trying strategies that simply do not work and wasting hundreds of dollars in the process.

According to Dr. Machael Cabana, a pediatrician at the University of Michigan’s C.S. Mott Children’s Hospital, who led the study, one of the most common mistakes was to buy mattress cover to protect against dust mites for a child whose asthma instead was made by plant pollen (花粉). Many of those parents then neglected to do what would have helped a lot more; shut the windows to keep pollen out. Another was using a humidifier for a child who was allergic to dust mites; a humidifier tends to be a place where dust mites like to breed. With those allergies, a dehumidifier works better.

Worst of all was the number of smokers with asthmatic children who didn’t even try to quit or at least limit themselves to smoking outdoors rather than just moving to another room or the garage. Many smoking parents purchased expensive air filters that have what Cabana called “ questionable utility. ”

Part of the problem, Dr. Caban and his colleagues believe, is that parents are bombarded by television ads that encourage them to buy products such as air and carpet fresheners, ionizers and other remedies that are often expensive but medically unnecessary. And doctors may not always take the time, or have the time, to explain to parents what will and won’t work in their child’s particular case. For example, allergies are usually a problem for older children with asthma, while kids 5 and younger more frequently have trouble with viral repiratory infections. So make sure you understand what the cause of your child’s asthma really is.

68．What can help the children who are asthmatic according to the passage?

A．Using a humildifier in the room instead of a dehumidfier.

B．Using air and carpet fresheners.

C．Buying a mattress cover to protect against dust mites.

D．Closing the windows to keep pollen out of the house.

69．Which sentence best explains why TV ads products bombard parents?

A．TV ads are obliged to make sure parents understand all terms of their introductory offers.

B．TV ads want to be sure that parents understand the benefits of very effective medical aids.

C．TV ads want parents to understand clearly the terms of their introductory offers.

D．TV ads want parents to be attracted to the benefits of introductory offers for their kid’s asthma.

70．The intended readers of the passage are ________.

A．teenagers              B．businessmen              C．parents            D．pediatricians

71．What can be inferred from the passage?

A．Therefore, please consult the doctors as soon as possible.

B．The best solutions are not always the most expensive ones.

C．It is never too late to cure the children’s asthma.

     D．It is not necessay for parents to be nervous about children’s asthma.