问题 选择题

下列变化中,发生了化学变化的是(  )

A.钢铁生锈

B.冰雪融化

C.干冰升华

D.矿石粉碎

答案

A、钢铁生锈的过程中有铁锈生成,属于化学变化,故A正确;

B、冰雪融化只是由固态到液态的变化,过程中没有生成新物质,属于物理变化,故B错误;

C、干冰升华的过程中没有新物质生成,只是发生了状态变化,属于物理变化,故C错误;

D、矿石粉碎只是固体颗粒由大到小的变化过程,过程中没有新物质生成,属于物理变化,故D错误;

故选A.

阅读理解

Do you know what school life is like in Singapore? In Singapore, a class only lasts half an hour, but there are no breaks between classes. The students only have a 30-minute tea break after 3 or 4 classes.

They do not do eye exercises. Yao Suyu said our eye exercises were unfamiliar(不熟悉)to her. “I’d like to introduce them to our school,” she said. “They’re very useful!”

In Singapore school ends at 1:50 p.m. But students joined other classes after school such as dance clubs and choir(合唱团). Yao says she joins dance club twice a week and it lasts from 1:30 to 5:30 p.m.

Singapore’s population(人口)includes Chinese, Indians(印度人), Malays(马来人 )and Westerners. But there is no special school for any one of the groups. The students in Yao’s school are mainly Chinese, Indians and Malays. “The Indian students take Indian language classes when we study Chinese,” said Yao. “But if an Indian student is interested in Chinese, he or she can study it, too.”

In Singaporean schools, teachers teach in English. It’s the official(官方的)language in Singapore. Singaporean students have to take different courses after school. Like most Singaporean students, Yao took other courses in Chinese, math and English.

小题1:How long does a class last in Singapore?

                                                                          

小题2:Do the students do eye exercises in Singapore?

                                                                          

小题3:When does school end in Singapore?

                                                                          

小题4:What does Singapore’s population include?

                                                                          

小题5:In which language do teachers teach in Singaporean schools?

                                                                        

问答题