17．Do you know how important it is to have breakfast？A study of 2，000teenagers in the US showed that eating breakfast daily is helpful to young people．
According to the study，teenagers who eat breakfast weigh around 5pounds less than teenagers who do not．Although they take in more calories （卡路里） in the morning，they are more active during the day because they have more energy．This means they burn more calories than non breakfast eaters．The breakfast does not even have to be very healthy，as eating anything is better than nothing．
The study also showed that eating breakfast keeps teenagers feeling full for longer，so they will not eat too many snacks （零食） later in the day．This is good news as most popular snacks，like sweets and potato chips，are usually unhealthy and full of calories．
Another big advantage of eating breakfast is that it helps teenagers do better at school．This is because it gives them more energy to keep their attention in class．
What's more，a study in the UK showed that adults （成年人） who eat breakfast daily put on less weight and also perform better at work．
Whatever your age is，take time to have breakfast every day．
21．The underlined sentence in Paragraph 2means thatC．
A．breakfast must be healthy with lots of calories
B．breakfast helps teenagers do better at school
C．teenagers should eat something for breakfast
D．the energy makes teenagers active the whole day
22．Having breakfast daily makes the teenagersB．
A．put on more weight
B．eat fewer snacks
C．relax themselves
D．burn less calories
23．The passage is mainly aboutA．
A．the advantages of having breakfast
B．how the adults perform at work
C．the importance of snacks
D．losing weight without breakfast
24．We can probably read this passage in a （an）C．
A．story book
B．movie poster
C．health magazine
D．instruction book．
分析 本文是一篇科教類閱讀，主要講述吃早餐對于青少年的重要性．吃早餐不但不會發(fā)胖，還提供給青少年足夠的能量使他們在課堂上集中注意力．然而，青少年們常吃的一些零食不僅沒有營養(yǎng)，反而會使人發(fā)胖．
解答 21．答案：C．句意理解題．這句話的意思是：不是吃早飯一定會讓你健康，但是吃總比不吃好．言外之意，就是青少年應(yīng)該吃早餐．故選C．
22．答案：B．細(xì)節(jié)理解題．The study also showed that eating breakfast keeps teenagers feeling full for longer，so they will not eat too many snacks （零食） later in the day．"研究還顯示吃早餐是的青少年飽腹感更持久，所以白天時就不會吃太多零食．"故選B．
23．答案：A．主旨大意題．閱讀全文，根據(jù)文章內(nèi)容可知，本文主要講述吃早餐的好處和必要性．故選A．
24．答案：C．推理判斷題．題意是：這篇文章很可能出自于哪？A．故事書；B．電影海報；C．健康雜志；D說明書．本文介紹的是吃早餐的好處，和人們的健康有關(guān)，由此可以推斷選C．故選C．
點(diǎn)評 本文是一篇科教類閱讀，題目涉及多道細(xì)節(jié)理解題，句意理解題，主旨大意題，推理判斷題．做題時學(xué)生應(yīng)仔細(xì)閱讀原文，把握文章主要內(nèi)容，聯(lián)系文章上下文內(nèi)容并結(jié)合所給選項(xiàng)含義，從中選出正確答案，一定要做到有理有據(jù)，切忌胡亂猜測．
