A:在任何化学反应中,只要提高反应温度,就可提高反应速率
B:在任何化学反应中,只要增大某一反应物的用量,就会增大反应速率
C:在任何化学反应中,增大压强时,都会使反应速率增大
D:在任何化学反应中,只要缩小容器的体积,都会使反应速率增大
下面四个图中所涉及的科学知识描述不正确的是( )
完成下列证明:如图,E点为DF上的点,B为AC上的点,∠1=∠2,∠C=∠D.
试说明:AC∥DF
解:∵∠1=∠2,(已知)
∠1=∠3(____)
∴∠2=∠3,(等量代换)
∴____∥____,(____)
∴∠C=∠ABD,(____)
又∵∠C=∠D,(已知)
∴∠D=∠ABD,(____)
∴AC∥DF.(____)
先通读下面的短文,掌握其大意,然后根据短文内容和所给首字母,在空格内填入一个适当的词,使短文意思完整。所填单词在答卷横线上必须完整写出。 I still remember visiting Moscow. It is the c ____ of Russia(俄罗斯), the b ____ country in the world. I go there with my parents at the age of eight. I live and study there for one year, I have some happy memories(记忆). One of the most interesting things of that city is that ,t____ are many dogs. Perhaps Russians l ____ dogs very much. You can see dogs here and there. Almost each of the families has a dog. I make friends with many Russian children w____ I am living and studying there. They are all very nice. They have fair hair and fair skin. I play with them h____ though(尽管)I can only speak a little Russian at first. They are f ____ to me. The weather in Moscow is very cold. It snows almost every day in w____ . The ground is always covered with a lot of snow. We often make snowmen t____ . Now I am b____ in China, but I miss them so much. I will never forget my happy memories of this visit to Moscow.