What are the keywords in the following sentence? the house is a living museum of art .
art, house, live, museum

What are the keywords in the following sentence? serving in the restaurant on a sunny day .
day, restaurant, serve

What are the keywords in the following sentence? ships travelling in convoy dot the horizon through rough seas
horizon, sea, travel

What are the keywords in the following sentence? layers of clouds at different heights in the sky
cloud, layer, sky