No.
At the time Michael Criton wrote Jurassic Park, the answer was not known. In response to the book, geneticists actually examined insects in amber and extracted DNA from them. What they found was that the DNA had degraded so much over time that there were so many holes that it would not be usable for cloning.

Now, Criton did consider this when he wrote Jurassic Park; this is why DNA from other animals (most notably frogs) was included in the dinosaur DNA: there were holes that needed to be filled. But the DNA in amber is so poorly preserved that if you tried to make an animal out of that using that technique, what you would wind up with would be a bird/reptile/frog, whatever DNA you used to patch the holes, with a few dinosaur-like characteristics, and not a dinosaur with a few frog-like characteristics.

Of course, birds ARE dinosaurs, so it might be possible to reconstruct some of the birds' ancestors by playing with their genes and turning things on and off (yes, genes can be turned on and off). You would not be able to get a triceratops this way, since the dinosaurs that gave rise to birds were not closely related to triceratops - but you might be able to get something like a velociraptor, which was actually very closely related to birds.

Possibly. At present it is very difficult to grow animals in a lab. Something about a mother's womb is very difficult to reproduce. All the successful techniques thus far have involved putting an animal's egg cell into a uterus for growth. But even once that barrier is crossed you have the problem of reconstructing the dinosaurs genome. If you found a mosquito in amber with blood from a dinosaur whose DNA was partially intact maybe you could do it. But it would depend entirely on what part was intact and what you would still consider to be a dinosaur.

You can certainly splice together parts of DNA to construct a genome again. But lets say that the entirety of the DNA coding for internal organs were missing and you had to replace them with the DNA from a frog as I believe they claimed in the movie. Would you consider a beast that externally appeared to be a dinosaur but had all the internal organs of a frog to be a dinosaur? There are many hurdles to overcome before we could have the technology to make dinosaurs from nothing.

If this is a question for the class you may also want to consider the consequences of bringing back some of these dinosaurs. What would happen in a world where they had no natural enemies and their food sources were all gone? Would the carnivores become the lion of the African savannah? Would an Apatosaurus out compete the Giraffe and drive them to extinction? Or would these dinosaurs not be able to cope with today's climates as compared to their own and die off almost immediately?