A small DNA molecule was cleaved with several dierent restriction nucleases, and the size of each fragment

A small DNA molecule was cleaved with several different restriction nucleases, and the size of each fragment was determined by gel electrophoresis. The following data were obtained.
Enzyme Fragment Size (kb)
Eco RI ................................. 1.3, 1.3
Hpa II ..................................... 2.6
Hind III ................................... 2.6
Eco RI + Hpa II ............... 1.3, 0.8, 0.5
Eco RI + Hind III ............ 0.6, 0.7, 1.3
(a) Is the original molecule linear or circular?
(b) Draw a map of restriction sites (showing distances between sites) that is consistent with the data given.
(c) How many additional maps are compatible with the data?
(d) What would have to be done to locate the cleavage sites unambiguously with respect to each other?