【简答题】If your child has mobile internet access, it will be more difficult to monitor(监督) and control his or her internet use. Kids are turning to the internet for everything from hanging out with friends to...
【简答题】If you go to Egypt, you'll see a lot of pyramids . The biggest of all is the Great Pyramid; it is about 137 meters high and made of 2,300,000 big stones. Each stone weighs about two and a half tons .T...