This first example demonstrates how to wait for seven seconds between two lines of speech. Example Request 
from plivo import plivoxml

response = (plivoxml.ResponseElement()
            .add(plivoxml.SpeakElement('I will wait 6 seconds starting now.'))
            .add(plivoxml.WaitElement(None).set_length(6))
            .add(plivoxml.SpeakElement('I just waited 6 seconds.')))
print(response.to_string())
Response 
<Response>
    <Speak>I will wait for seven seconds starting now.</Speak>
    <Wait length="7" />
    <Speak>I just waited seven seconds.</Speak>
</Response>