题目

用简便方法计算下面各题。（1）202×85 （2）53×25×40 （3）389－132－168（4）720 ÷48 （5）48×101－48 （6）360÷8＋5 答案：【答案】（1）17170；（2）53000；（3）89（4）15；（5）4800；（6）50【解析】（1）将202写成200＋2，运用乘法分配律化简计算；（2）运用乘法结合律计算，先计算25×40；（3）根据减法的性质进行计算；（4）将48写成8×6，根据除法的性质进行计算；（5）运用乘法分配律进行计算；（6）除法与加法的混合运Do you get stressed out sometimes ? Are you confused about what is really important in   31   life ? Don ' t worry . You are not alone ! Many teens say they have a lot of stress in their lives. Homework , friends and busy schedules can make anyone feel down . The good   32   is there are lots of ways to reduce stress. Here are just  33   suggestions . First of all, what shouldn't you do ? Well , you shouldn't stay out   34  . Going to parties and hanging out with friends are fine when you are feeling well ,but you should not do these things too often when you are stressed out .   35 , you should not get too nervous about school stuff. Schools and school activities are an important part of your life , but you should not worry about homework .  36  . You have to enjoy other things in life ,too! What should you do ? Most importantly, you should be good to your body . Take it easy sometimes. Listen to some music and maybe   37   your friends . Another piece of good advice is to get outside and exercise! Go hiking or camping , play a sport for  38  . Do something active and you will soon forget the  39   and remember — when you are really stressed out , go to bed and get some __40__ . Most problems usually seem better in the morning . 31.A. your              B. his                C. her 32.A. ideas             B. news               C. keys. 33.A. any               B. much.              C. some. 34.A. late              B. last.              C. early. 35.A.too.               B. also.              C. either. 36.A. too many          B. much too.          C. too much 37.A. talk with         B. talk about         C. talk aloud. 38.A. work              B. fun                C. money. 39.A. time              B. advice.            C. Stress. 40.A.sleep              B. food               C.fruit