If you’ve ever wondered how often you should shampoo (用洗发剂洗) your hair, you’re not alone. 【小题1】 While many people prefer to wash their hair daily, others think that once every few days is best. But that still leaves us with the very important question - how much is too much?

【小题2】 When you wash your hair with shampoo, the surfactant (表面活性剂) in the shampoo mixes with water and works to clean dirt and oil from your hair. Although clean hair is definitely a good thing, frequent shampooing can lead to some problems such as split ends (发梢开叉) and dull hair.

Most people who wash their hair every day say they do it to avoid a build-up of oil. But in fact, skipping a wash is the best way to prevent oil from building up. Most often the oily substance in your hair doesn’t come from natural oil but from the products you use for treatment and styling. 【小题3】

Actually, how often you should shampoo your hair depends on your hair type. People who sweat a lot or live in a humid area may need to shampoo their hair more frequently. 【小题4】 If your hair is oily, you should try to use a shampoo that is specially designed for oily hair.

Since thicker hair collects less oil, it’ll need less washing. 【小题5】 Anyway, the best way to know how often to wash your hair is to experiment. As long as you don’t have scalp (头皮) problems, you can wash your hair once a week.

In 2016, nearly 57 percent of American households owned a pet, according to the American Vets （兽医）Medical Association, but it's safe to say that 100 percent of them wish their dog or cat to live longer. In fact, advances in veterinary medicine have made it easier than ever to lengthen your pet's life. However, there are so many care options available that finding the ones that are worthwhile for your pet can be time-consuming. 【小题1】

Watch Their Weight

About 60 percent of cats and 56 percent of dogs are over-weight or obese. 【小题2】 For example, overweight increases the risk of conditions like diabetes （糖尿病）,some cancers, and certain breathing problems. And being overweight shortened dogs’ life by up to 2.5 years compared with their ideal-weight peers.

Visit the Vet

【小题3】 " Because pets age more quickly than humans, their problems may worsen fast. ” says Pete Lands, director of emergency at Saint Francis Veterinary Center in Swedesboro, New Jersey. So keep up on routine treatments.

【小题4】

Pets need daily workouts to stay healthy, so a formal workout plan is a good idea. Aim for between 30 minutes and two hours of daily activity, such as walking or running. Athletic breeds will require more exercise, while smaller dogs such as bulldogs can benefit from a short walk around the neighborhood. And believe it or not, some devices can track your pet's steps, heart rate, and other indicators.

Brush Their Teeth

According to Banfield Pet Hospital, 68 percent of cats and 76 percent of dogs have dental disease. 【小题5】 To avoid that, brush your pet's teeth every day. You should also get your pet's teeth professionally cleaned by your vet at least once a year.

Necessary things for travel

Personal alarm

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$14.99

When you're traveling alone, particularly to a place that you know little about, it's important to give yourself peace of mind in terms of safety. A wearable personal safety alarm is a great idea.

It hugely adds to your sense of control on many a dark street and crowded public space. You can sleep with it under your pillow no matter what country you are in.

Portable charger

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$27.95

With our phones acting as our lifelines, traveling with one at low battery can make you stressful and, if an emergency （紧急 情况）occurs, even dangerous. Keeping a portable charger on hand to give your phone the juice it needs to be useful is important, and it won' t take up much space in your bag at all. The peace of mind is worth it.

Hand sanitiser (消毒液)

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$12.99

As a traveler, you should always carry hand sanitiser. It's small enough that you can't even notice it in a pocket of your bag, and it's totally fine to take through any airport. When it comes to hygiene-related (卫生相关的) emergencies, you really can't do without it. Believe it or not, alcohol- based hand sanitiser can even help you get a fire started, which could, of course, be important in a survival situation.

Reusable water bottle with Alter (过滤器)

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$36.84

As anyone who's traveled in the past two decades knows, liquids above the 3. 4-ounce limit will be taken away at the security checkpoint. Carry a reusable water bottle that includes a filter. Easy access (接近) to water in case you are short of it, especially in an emergency, is a lifesaver. Again, it's simple and easy to carry without any problems when it is checked.