题目

一遥控玩具小车（视为质点）从 时刻开始向某一方向运动，运动的位移—时间图像（ 图像）如图所示，其中曲线部分是抛物线，曲线之后的图线是平行于时间轴的直线，直线与抛物线平滑连接。下列说法正确的是（） A . 小车先做匀加速直线运动后做匀速直线运动 B . 小车先做匀減速直线运动后保持静止 C . 小车先做变加速直线运动后做匀速直线运动 D . 小车一直做初速度为零的匀加速直线运动Fire can help people in many ways． But it can also be very harmful (有害的)． Fire can keep your house  1  , give light and cook food ． But fire can burn things  2  ．Big fire can burn ,trees ,houses , animals or people ． Nobody knows how people began to use fire ．But there are  3  ．interesting old stories about how a man or woman started a fire ．One is  4  a man ． The man  5  a very long time ago ． He went up the sun and  6  fire down． Today people know how to make a fire with matches(火柴)． Children sometimes  7  to play with them ． But matches can be very dangerous． One match can burn a piece of paper． And  8   it could burn a house． A small fire can turn a big fire． very quickly． So you    9  be careful with matches． Be careful with fire , and it will  10  you ．But if you aren’t careful with fire ． and it may hurt you． 1．A． warm 　　B． warmer 　　 C． cool 　　　　D． cooler 2．A． also 　　　B． too 　　　　C． either 　　　D．neither 3．A． many 　　B． much 　　　 C． little　 　　 D． no 4．A． over 　　 B． about 　　　 C． a little 　　 D． no 5．A． worked 　B． studied 　　　C．learned 　　 D． lived 6．A． bring　　 B． take 　　　　C． brought 　　D． took 7．A． enjoy 　　B． like 　　　　C．don‘t like 　　D． become 8．A． after 　　B． late 　　　　 C． yet 　　　 D．then 9．A ．can 　　 B． man 　　　　 C． will 　　　　D． must 10．A． help 　　B． do 　　　　　C． tell 　　　　D． hope