Self-driving is an area China and the rest of the world are on the same starting line. (填关系词或“介词+关系代词”)

已知锐角三角形三边分别为3，4，a，则a的取值范围为（   ）

People r to the speech in different ways some got angry, others nodded.

This question (discuss) at the meeting yesterday.

他搬到了乡村，想寻找一种平静的生活。

He moved to the countryside a peaceful life.

阅读理解。

    Youth sport has the potential to accomplish three important objectives in children's development. First, sport programs can provide youth with opportunities to be physically active, which can lead to improved physical health. Second, youth sport programs have long been considered important to youth's psychosocial development, providing opportunities to learn important life skills such as cooperation, discipline, leadership, and self-control. Third, youth sport programs are critical for the learning of motor skills; these motor skills serve as a foundation for future national sport stars and recreational adult sport participants. When coachers develop activities for youth practices and when sport organizations design youth-sport programs, they must consider the implication of deliberate play and deliberate practice.

    Research from Telama （2006） states that regular participation in deliberate play or deliberate practice activities during childhood and youth （ages nine to eighteen） increases the likelihood of participation in sports during adulthood by six times for both males and females. Côté （2002） defines deliberate play activities in sport as those designed to maximize enjoyment. These activities are regulated by flexible rules adapted from standardized sport rules and are set up by the children or by an involved adult. Children typically change rules to find a point where their game is similar to the actual sport but still allows for play at their level. For example, children may change soccer and basketball rules to suit their needs and environment （e.g. in the street. on a playing field or in someone's backyard）. When involved in deliberate play activities, children are less concerned with the outcome of their outcome of their behavior. （whether they win or lose） than with the behavior. （having fun）.

    On the other hand, Ericsson （1993） suggests that the most effective learning occurs through involvement in highly structured activities defined as deliberate practice. Deliberate practice activities require effort, produce no immediate rewards, and are motivated by the goal of improving performance rather than the goal of enjoyment. When individuals are involved in deliberate play, they experiment with different combinations of behaviors, but not necessarily in the most effective way to improve performance. In contrast, when individuals are involved in deliberate practice, they exhibit behavior. focused on improving performance by the most effective means available. For example, the backhand skills in tennis could be learned and improved over time by playing matches or by creating fun practice situations. However, players could more effectively improve their backhand performance by practicing drills that might be considered less enjoyable. Although drills are used in most effective means available practice might not be the most enjoyable, they might be the most relevant to improving performance.

    （Note: Answer the questions or complete the statements in NO MORE THAN TEN WORDS）

将32.64g铜与140ml一定浓度的硝酸反应，铜完全溶解产生的NO和NO₂混合气体在标况下的体积为11.2L，问NO的体积是多少L？NO₂的体积为多少L？

将一定量的乙烷完全燃烧，使所有的气体按顺序通过装有无水氯化钙和氢氧化钾的硬质玻璃管，氢氧化钾管的质量增加了4.4g，则乙烷在标准状况下体积（   ）

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    There is an English saying:“.” Until recently, few people took the saying seriously. Now, however, doctors have begun to look into laughter and the effects it has on the human body. .

    Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their hearts, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise. . If laughter exercises the body, it must be beneficial.

    Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group that tolerated(忍耐) the pain for the longest time was the group which listened to a funny program. .

    . They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

A. Laughter can make one's life longer.

B. As a result of these discoveries, some doctors in the United States now hold laughter clinics in which they help to improve their patients' condition by encouraging them to laugh.

C. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which reduce both stress and pain.

D. It increases blood pressure, the heart beating and breathing; it also works several groups of muscles in the face, the stomach and even the feet.

E. Although laughter helps cure the disease, doctors still can not put this theory into clinic practice.

F. Laughter is the best medicine.

G. They have found that laughter really can improve people's health

Can you help me (gather) some information on Chinese traditional festivals?

下面一段文字在标点、语言表达等方面存在多处错误，请至少指出四处并加以改正。

“中学生阅读导报”自创刊以来，一直深受广大莘莘学子的喜爱。明年，我报社将不孚众望，继续狠抓内部管理和刊物质量为中心，进一步提升报纸品位，向读者奉献更加精美的精神食粮。最近，有些读者反映没收到近期的报纸，为了防止这类事情不再发生，今后我们将优化发行方式。

This job is so boring. I wish I could do something more c.

若点O是△ABC所在平面内的一点，且满足|﹣|=|+﹣2|，则△ABC的形状为 

把6.5gZn放入足量的稀盐酸中，锌完全反应．计算

阅读下面的文字，按要求写作文。

“我梦想有一天，幽谷上升，高山下降，坎坷曲折之路成坦途，圣光披露，满照人间。”（《我有一个梦想》），人生应该有梦想，但人生最缺少的有时就是梦想。马丁．路德．金的《我有一个梦想》从教材中删除了，但人生的梦想却不应该被删除。请以“留一点梦想给自己”为题目写一篇不少于700字的记叙文。

要求：选好角度，确定立意；‚适当运用描写、抒情等表达方式，写出事件的波澜或展现人物的特征；ƒ不得抄袭和套作，不得透露个人相关信息。

This English dictionary is expensive, but it is of ________.

我去过那儿很多次了,我们还是换个地方吧。

某化学小组为了研究外界条件对化学反应速率的影响，进行了酸性高锰酸钾与草酸的反应，记录以下实验数据：

实验编号	实验温度	试管中所加试剂及其用量 / mL				溶液褪至无色所需时间/ min
		0.6mol/L H2C2O4 溶液	H2O	3mol/L H2SO4 稀溶液	0.05mol/L KMnO4溶液
①	25	3.0	V1	2.0	3.0	1.5
②	25	2.0	3.0	2.0	3.0	2.7
③	50	2.0	V2	2.0	3.0	1.0

近年来, 很多中小学组织学生开展研学旅行活动, 通过游览、交际, 来认识自然和社会。你校也计划开展此项活动, 但是有些学生表示欢迎，也有些表示反对。请你写一篇120词左右的英语文章 (题目已给出), 谈谈你的看法并说明理由。My View on Study Tour

从某微粒的原子结构示意图反映出（   ）