selenium click on button when he is in frame : i tried to enter this website : https://www.google.com/recaptcha/api2/demo
and click on this button :


[![enter image description here][1]][1]


than, i tried to click on this button :

[![enter image description here][2]][2]


and finally , on this button : 

[![enter image description here][3]][3]


  [1]: https://i.stack.imgur.com/0q229.png
  [2]: https://i.stack.imgur.com/LvTjG.png
  [3]: https://i.stack.imgur.com/TO0kD.png


i used this code - 

     driver1 = webdriver.Firefox()
     driver1.get("https://www.google.com/recaptcha/api2/demo")
     driver1.switch_to.frame(driver1.find_element_by_css_selector('#recaptcha-               
     demo > div:nth-child(1) > div:nth-child(1) > iframe:nth-child(1)'))
     driver1.find_element_by_xpath('//*[@class="recaptcha-checkbox-
     checkmark"]').click()
     time.sleep(4)
     driver1.switch_to.default_content()
     driver1.switch_to.frame(driver1.find_element_by_css_selector("body >      
     div:nth-child(2) > div:nth-child(4) > iframe:nth-child(1)"))
     driver1.find_element_by_xpath('//*[@id="recaptcha-audio-button"]').click()
     driver1.find_element_by_css_selector('.rc-audiochallenge-tdownload-link').click()

Unfortuently it clicked only on the first and the seconde button but not on the third , sombodey know why?
I checked and the seconde button and the third are in the same frame , so its sound strange , mabye im worng? 