Measuring time

This task is about different ways to measure time.

Question 1Change answer

illustration: sundial
a)  How does this measure time?

Question 1Change answer

illustration: hour glass
b)  How does this measure time?

Question 1Change answer

illustration: burning candles
c)  How does this measure time?

Question 1Change answer

illustration: clock
d)  Here is a picture of a modern way which is used to measure time.
     What are the advantages of this way of measuring time?
What are the disadvantages of this way of measuring time?