西瓜的果实里有许多种子，这是因为西瓜花的子房里有______个胚珠．
在花的结构中，花蕊是花的主要部分，因为它与果实和种子的形成有关．当传粉和受精完成以后，花的各部分发生了变化．
花萼凋落或存留，花冠凋落，雄蕊凋落，雌蕊的柱头和花柱凋落，只有子房继续发育．子房由子房壁和胚珠构成，子房壁发育成果皮，胚珠发育成种子，这样子房就发育成了果实．种子的数目是由胚珠的数目决定的．
故答案为：多
| 阅读下面的短文，完成测试任务。 | ||
| 1. The weather report, a story about the Pop stars and different cultures are examples of messages from the media. Examples of media are television, radio, newspapers and books and the telephone. The media that can reach many people at once are called mass media. 2. It is not difficult to think of other messages we receive through the mass media. Every day we get hundreds of them. Think about ads, for example. We see and hear these messages almost everywhere we go. Ads are important messages. Even though they sometimes make us feel rather angry, they help us know things well. 3. Most of us get more information from the media than from the classroom. Think, for a moment, about how you learn about news and events. Do you learn them from other people or the media? What about international news? What is the most important place of information for you? People who are asked this question usually answer, "Television." 4. Think of all the messages you received today. Perhaps you read a newspaper during breakfast, or maybe you read ads on billboards on your way to school. Did you listen to a weather report or the sports news on the radio this morning? Now you are reading, and that's to say you're getting information through a very important medium of mass. 5. The mass media are important to us because they shape our decisions and opinions. 注：(1) media 传媒 (2) mass media 大众传媒 (3) billboards 露天广告 (4) shape 影响 | ||
从所给的3个选项中分别为第2和第4段选择1个正确的小标题。其中一项多余。
2. Paragraph 4: _____ 从所给的5个选项中选择3个正确的选项，分别完成下列句子。其中两项多余。
4. For most people television is the most important _____. 5. The mass media are important to us because they shape _____. |