Australian lungfish are unable to survive while breathing only air. Australian lungfish are able to survive prolonged periods of drought by burrowing into the mud at the bottom of their drying pond and by remaining there until rains refill the pond the following year. Australian lungfish live in saltwater whereas the African and South American lungfish occupy only freshwaters. Australian lungfish do not actually possess lungs. The same animal will be neutrally buoyant at a depth of 10 meters when its swimbladder has a volume of a. 4 cm 3 .
Students sometimes become ill just before a scheduled exam.
If illness overtakes you at such a time, do not force yourself to come to class to take the test. People who are ill commonly do poorly on tests, and we do not want you to do poorly because of a problem with your health. You will be required to present evidence that you were, indeed, ill at the time of the exam. Unfortunately, we have no way to offer a make-up exam that would be comparable to the exam taken by other students in the class, and therefore will estimate the score for the missed exam from your performance on the other three exams. Should you be so unfortunate, however, as to miss two exams because of illness, we will report a grade of Incomplete to the Registrar.