I have a few of the blanks filled, but I need help for the rest of these.

If a wave source is moving towards an observer, that observer senses a _______ wavelength, and a _______ frequency. So Observer B would hear a sound which was at a _______ _______ than the actual sound. Observer A sees the source moving away, and would hear a sound which had a ____________ wavelength, and had a _________ frequency, which sounds like a ________ _________