"Smart" devices can gather video or other （1）

i and share it over the internet， making our lives easier. But they may also invite hackers into our homes.

In October 2016， hackers hit a company called Dyn. After the hack， people around the world had trouble getting to many （2） w ， including Amazon， Netflix and Twitter.

But please don't think that hackers are only interested in using people's devices， mostly smart

（A） d ， to attack a company. Hackers can use those devices to hack individuals and get into our homes too.

But how can we keep hackers away from our homes？

One （3） s is easy： Change your password. "People don't like passwords，" Hong says. Many people use the same password for years. Moreover， many people choose passwords that are remarkably simple， he adds — "like 12345， or their names." To make a device more secure， change each （B）

p often and choose （C） s a hacker can't guess.

Smart devices you tend to buy pose a potential

（D） d . It is tempting for you to buy new smart gadgets. And it can be hard to tell which are secure. That's why many scientists recommend that people wait a few weeks after a new （4） g appears before buying it. The general rule of thumb is： Don't be the first penguin in the water.

Now the security （5） p needs computer scientists who can think like hackers. They have to be able to find flaws in new smart devices. They look at a system and think， "how can they break it？ Is it really secure？"

Those questions are typical of scientists who study （E） s . These are people who can't help trying to break things all the time. That's the same thing a hacker wants to do. But instead of stealing data or interfering with a person's life， computer-security scientists want to make the world safer.

（A， B， C， D， E FOR CROSS， 1， 2， 3， 4. 5 FOR DOWN. The first letters of the absents were given.）