题目

下列叙述中正确的是() A . 和是中子数不同质子数相同的同种核素 B . 中子数为20的氯原子可以表示为 C . 同种元素的原子均有相同的质子数和中子数 D . F-的结构示意图可以表示为 答案：DA very important world problem is the growth of population on the earth. The population of the world today is more than 6,500,000,000. That is a great number and we know it quite well. ①The important thing is not how large the population of the world is now, but is the rate (速度) of the growth. It is about 1.63% every year after the number of dead people has been taken away.To give you some ideas of the birth rate, look at the second hand of your watch. Every second, four babies are born in the world. Another baby! Another baby! Another baby! Another baby! ②You can not speak quickly enough to keep up with the birth rate. The population is ③growing faster and faster. So it goes on, hour after hour. In one day, people have to find food for over 350,000 mouths more.This great growth of population will make a big problem by the year 2010—there will be as many as 7,000,000,000 people on the earth! So this is one of the biggest problems that you are going to meet in your life.根据短文内容，完成下列各题。1.What’s one of the important world problems today according to the passage?________________________________________________________________2.将文中①处画线的句子翻译成汉语。_________________________________________________ 3.将画线句子②改为意思相同的句子。You speak slowly you can’t keep up with the birth rate.4.写出与划线部分③意思相同的单词。__________________________________________________________________5.From the passage, how many new babies are there to be born in a minute?__________________________________________________________________