My town is a great place to live in. It's the best place to enjoy your free time. There are three movie theaters in the town. They are all good, but the one nearest my house is the best. Shopping is also easy. There are many shops and most of them are trendy. They sell very fashionable clothes. They are also cheaper than those in other cities, so students love to shop here. There are also a lot of video and music stores. These are very popular with students. I go to the music store every week to buy a new CD. The most crowded place for students to hang out is the park. Everyone goes there, so it's really interesting.

    Sometimes there are even street performers. Some students think they are boring, but I think they are the most creative people. I want to be a street performer, too.

《大国崛起》解说词中说到：“公元1500年前后的地理大发现，拉开了不同国家相互对话和相互竞争的历史大幕”。实现“地理大发现”的历史事件是（    ）

如图，将两个底面平整、干净的铅柱紧压后，两个铅柱就会结合在一起，即使在下面吊一个较重的物体也不会将它们拉开．这个实验表明（　　）

我国人口的突出特点是（    ）