A、Toillustrate that theembryofossilsarequiteadvancedin theirdevelopment.
B、To explain why the fossils are well preserved
C、To explain why the fossils are well preserved
D、To prove thatichthyosaursare marineanimals
Task 221.For as long as three months of a year, the sun_________on the ice-covered land of Alaska22.Accordingtostatistics,_________of the total area of Alaska has been used for farming, 23.Alaska was originally part of Russia, but was bought_________24.Gold did not bring to Alaska as much wealth_________25._________has become Alaska'ssingle important resource.A. as fish doesB. oilC. by the United States in the 19th centuryD. shines day and nightE. only a very small percentageF. a limited amount of the gold found there