if r.status_code in (429, 503):
习题链接：LeetCode 853. 车队
。WPS官方版本下载对此有专业解读
不久前又收到桂红的短信。桂红说，您好好休养，待到春暖花开，您约褚老师一起来我们湖北宜城宋玉中学吧，看看打工子弟的孩子们，给他们捐点书、讲讲课，好吗？
Tracy Hinds Chair, Open Source Initiative
Microbiologists have been growing microbes on agar plates for nearly 150 years, but agar’s discovery dates back to a happy accident in a mid-17th-century kitchen. Legend has it that on a cold winter day, a Japanese innkeeper cooked tokoroten soup, a Chinese agar seaweed recipe known in Japan for centuries. After the meal, the innkeeper discarded the leftovers outside and noticed the next morning that the sun had turned the defrosting jelly into a porous mass. Intrigued, the innkeeper was said to have boiled the substance again, reconstituting the jelly. Since this discovery, agar has become a staple in many Japanese desserts, from yokan to anmitsu.