将函数的图象向左平移个单位,得到函数的函数图象,则下列说法正确的是( )
观察下列等式:
;
;
;
照此规律,___________.
已知函数满足,若函数与图像的交点为,,,,则( )
方程在区间上的解为__________.
Have your parents ever inspected your room to see if you cleaned it properly? Imagine having your entire houses, garage, and yard inspected at any time -- with no warning. Inspections were a regular part of lighthouse (灯塔) living, and a keeper's reputation depended on results. A few times each year, an inspector arrived to look over the entire light station. The inspections were supposed to be a surprise, but keeper sometimes had advance notice.
Once lighthouses had telephones, keepers would call each other to warn that the inspector was approaching. After boats began flying special flags noting the inspector aboard, the keeper's family made it a game to see who could notice the boat first. As soon as someone spotted the boat, everyone would do last-minute tidying and change into fancy clothes. The keeper then scurried to put on his dress uniform and cap. Children of keepers remember inspectors wearing white gloves to run their fingers over door frames and windowsills looking for dust.
Despite the serious nature of inspections, they resulted in some funny moments. Betty Byrnes remembered when her mother did not have time to wash all the dishes before an inspection. At the time, people did not have dishwashers in their homes. In an effort to clean up quickly, Mrs. Byrnes tossed all the dishes into a big bread pan, covered them with a cloth and stuck them in the oven. If the inspector opened the oven door, it would look like bread was baking. he never did.
One day, Glenn Furst’s mother put oil on the kitchen floor just before the inspector entered their house. Like floor wax, the oil made the floors shiny and helped protect the wood. This time, though, she used a little too much oil. When the inspector extended his hand to greet Glenn's mother, he slipped on the freshly oiled surface. "He came across that floor waving his arms like a young bird attempting its first flight," Glenn late wrote. After he steadied himself, he shook Glenn's mother's hand, and the inspection continued as though nothing had happened.
闻名于世的丝绸之路是一系列连接东西方的路线。丝绸之路延伸6,000多公里。得名于古代中国的丝绸贸易。丝绸之路上的贸易在中国、南亚、欧洲和中东文明发展中发挥了重要作用。正是通过丝绸之路,中国的造纸、火药、指南针、印刷等四大发明才被引介到世界各地。同样,中国的丝绸、茶叶和瓷器(porcelain)也传遍全球。物质文化的交流是双向的。欧洲也通过丝绸之路出口各种商品和植物,满足中国市场的需要。