1 . Wrinkles, losing skin, fine lines and creases (折痕) are parts and parcels of growing older.    1    Here are many ways to start tackling the signs of aging before it's too late, and those methods extend past the old and tired advice of “go to bed early, ”and “drink more water.”

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Countless studies have found that adults who participate in what they see as stimulating and meaningful activities experience less inflammation (炎症).    3     Picking up a new hobby doesn't necessarily have to be something physically or financially demanding. It can be as simple as diving into a new type of literature than what you normally read, getting around to using that painting kit you've had sitting around for a few years, or baking a new recipe on a random Thursday night.

Switch up how you sleep

    4    “Crunching” your face on the pillow creases your skin over time, which can lead to wrinkles and fine lines. Dr. Jaliman recommends sleeping on a silk pillowcase, which provides more “slip” than cotton and nylon materials, and sleeping on your back if possible. It's a little lifestyle change, but it can make a big difference in your skin's overall appearance.

Don't skip the dentist

Speaking of health, did you know that investing in proper dental care is also investing in your skin's anti-aging powers? Not taking care of your teeth ages your smile and can also cause nutritional drawbacks and infections, both of which will definitely show on your skin. In addition to caring for your teeth daily, make sure you're visiting your dentist regularly and getting x-rays as needed.    5    

A．Turn to new interests.

B．Avoid physical exercise.

C．Having no enough sleeping may wrinkle your skin.

D．It can decrease physical stress contributing to aging of skin.

E．However, that doesn't make them any more pleasant to deal with!

F．They can easily catch and prevent any deeper dental issues.

G．People who sleep on their sides are more likely to experience skin wrinkling.

2 . It seems that everyone seeks for bright white teeth. There are whitening materials in toothpastes, mouthwash, and even chewing gum. Yellow teeth seem to get a bad reputation and are usually associated with poor oral hygiene (卫生) . Fortunately, we have some good news for those who lack those pearly whites. Yellow teeth are actually stronger than bright white teeth!

We know, it's hard to believe. According to sciencefocus. com, the enamel (珐琅质) on your teeth is naturally a blueish white color and the dentine ( 牙质) beneath it is naturally yellow. Since the enamel is semitransparent, the yellow shows through the blueish white. This creates a light grey or light yellow color. However, if your teeth are significantly darker than a light yellow， there may be a potential cause such as disease or tooth decay.

The process of bleaching your teeth is what weakens them.“Some products contain hydrogen peroxide (过氧化氢) that spread through the enamel. It breaks down the compounds that are causing color changing, and your teeth become lighter, ”Adriana Manso, a clinical assistant professor in the Faculty of Dentistry, told The University of British Columbia.

“Those products can have multiple side effects such as damaging the dental enamel, causing harm to the gums, tooth sensitivity and more,” Manso adds.“Some of these effects are lasting; for example, the damage to the dental enamel is permanent and irreversible.

If you sill long for those white teeth though, there are plenty of chemical-free routes to take that won't damage your enamel一like eating celery, spinach, onions, carrots, shiitake mushrooms, peanuts or drinking green tea, or consulting a doctor to try, other more advisable ways to naturally brighten your teeth.

1. What can we learn from paragraph 1 and 2?

A．Yellow teeth are weaker than white ones.

B．People who have yellow teeth have a bad reputation.

C．The enamel and dentite beneath it are the same color.

D．Your teeth may become darker than a light yellow due to tooth decay.

2. What does the underlined word “bleaching” in paragraph 3 mean?

A．Whitening.

B．Brushing.

C．Strengthening.

D．Protecting.

3. Which is the proper way to whiten teeth according to this passage?

A．Drinking whatever you want.	B．Seeing a doctor for surgery.
C．Adopting approaches to protecting enamel.	D．Using some whitening oral products.

4. What does the passage mainly talk about?

A．The benefits of keeping yellow teeth.	B．The methods of whitening teeth.
C．The reasons for not whitening teeth.	D．The side effects of whitening teeth.