How many quarter notes would be found in a measure of music within the time signature 4/4

Look at las meninas by diego velasquez. this painting is a masterful example of the use of:

What fractionof the fifth frade students either ride the bus with r walk to school

Above is a picture of one of the most famous discoveries ever to be found in china. answer the following questions: - what does the picture show? - when and where was it discover? - who discovered it and what was he doing when he/she discovered it?