题干

下列关于细胞分裂、分化、衰老和凋亡的叙述,正确的是(  )

A:细胞分化使各种细胞的遗传物质产生差异

B:细胞的衰老和凋亡是正常的生命现象

C:细胞分化仅发生于胚胎发育阶段

D:所有体细胞都不断地进行细胞分裂

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B

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Ways to protect cell phones from damage

    While people use cell phones frequently, very few take the necessary measures to prevent damage. ____ Here are some simple ways for you to protect your cell phone from damage.

Keep cell phones out of the rain

    If you must talk on the phone while it's raining, try to move indoors.  ____ Otherwise, you may have trouble with the numbers or the cell phone speaker. Imagine dialing (拨打) one number and getting different results.

____

    Many people like to put their cell phones in the pants or jeans pocket. However, storing a cell phone there will put it at risk of damage. You may forget that it is still in your pocket and just sit on the cell phone. As a result, your cell phone screen will get damaged.

Do not handle cell phones while eating

    ____ This is especially true for those times when you are eating messy things and get the ingredients on your hands. One accident can cause lots of damage for your cell phone.

Get a protective cell phone case

    There are many kinds of cases available on the market. ____ It will provide a protective cushion (垫子) that may save you from paying money to fix or buy a new phone.

A. Do not put cell phones in your pocket

B. Do not throw cell phones onto hard surfaces

C. Many people often talk on the phone in the rain.

D. You can also cover the phone up with your hand.

E. Just choose one that fits the size of your cell phone.

F. One mistake may end up costing you more money.

G. Food and drinks should not be near your cell phones.