为什么Selenium驱动程序无法识别Facebook登录页面的ID元素？

要登录

Facebook

System.setProperty("webdriver.gecko.driver", "C:\path\to\geckodriver.exe");WebDriver driver =  new FirefoxDriver();driver.get("https://www.facebook.com/");driver.findElement(By.cssSelector("input#email")).sendKeys("Selenium");driver.findElement(By.cssSelector("input[name='pass']")).sendKeys("Automation");driver.findElement(By.cssSelector("input[value='Log In']")).click();