add method : List<WebElement> findElementListByClassName(WebDriver
driver,
String selector) 

add method : highLight(WebDriver driver, List<WebElement> list)
when start qunar, sleep 15 seconds.
add test case for testFindElementListByClassName();
Random.test
finish 75% of exam.there are two questions on it 
1.no search results
2.random 100 cities, in 3 months