题目

Complete the sentences with the given words in their suitable forms（用括号中所给单词的适当形式完成下列句子。每空格限填一词）【1】The teachers in our school are __________ in teaching and they all have a high sense of responsibility. （experience）【2】After the earthquake, many houses and schools are destroyed， they must be_______immediately.（build.)【3】As a ______ ,it’s necessary for you to take action to protect the environment. （city）【4】Millions of people in the world die of_______ every year. （hungry）【5】Finally, they found a ____观察下列图形和所给表格中的数据后回答问题．梯形的个数12345…图形周长58111417…（1）问当梯形的个数为10个时，图形周长为______；（2）当梯形的个数为n时，图形的周长为______．