问题 选择题

某生物一个体细胞中含有X条染色体,在细胞分裂过程中,染色体的数目变化情况是(  )

A.X→X→X

B.X→2X→2X

C.X→2X→X

D.2X→2X→X

答案

答案:C

题目分析:细胞核分裂时,染色体的变化最明显.染色体复制,DNA也随之复制为两份,平均分配到两个子细胞中,使得后代细胞染色体数目恒定,从而保证了后代遗传特性的稳定.故染色体的变化应该是:X→2X→X.

故选:C.

完形填空

Answer the questions(根据短文内容回答下列问题)

How much pocket money do you get? How do you spend it? The Blue Book of Chinese Teenager Financial(金融的) Study shows that social activities now take up more of teenagers’ spending. The book was about teenagers’ spending habits. It was based on studies in nine cities in China, such as Beijing, Shanghai and Guangzhou. The results show that students are spending more and more on their relationships with friends and classmates, such as having meals together and buying birthday gifts. Only one-third of high school students think about the price when choosing gifts. Most say they only care about what their friends like.

Xiao Hao, 17, a student at Gaoyou Normal School in Jiangsu, spent more than 1,000 yuan on his birthday meal this February. “They had given me gifts. If I hadn’t done anything in return, I’d have lost face,” Xia said.

Xia’s experience is quite usual among the young students. A meal can cost a student’s pocket money for a month. Many just ask more from parents when they use up their money.

Zhang Wei, an expert on teenagers’ financial study, suggested that teenagers should learn to make a budget. A budget is a plan of how money will be spent. It helps make decisions about money. To make good use of your money, you can also set a limit. Learn to balance your wants and needs. When choosing gifts for friends, let them know that you care. Sometimes a handmade gift is much better than an expensive one.

小题1:Were there 3 cities in China taking part in the study?(1分)

____________,_______________________________________________________.

小题2:According to the results, how do students spend most their pocket money? (2分)

_____________________________________________________________________.

小题3:Which do most students consider when choosing a gift, the price or the things their friends like?(2分)

_____________________________________________________________________.

小题4:How much money can a meal usually cost? (2分)

_____________________________________________________________________.

小题5:What suggestions are given in the passage to help students make good use of the pocket money? (2分)

_____________________________________________________________________.

小题6:Which of the given suggestions do you think is the most useful to you? Why? (3分)

I think______________________________because___________________________.

单项选择题