A、The discovery of oil B、The interest in wildlife. C、An increase in the birthrate. D、An improvement in building materials. A

Good afternoon. Today I want to say something about Alaska. One thing that concerns me most is the future of the Alaskan environment. About 25 years ago, before going on a wilderness research trip, I visited Anchorage, the largest city in Alaska. It was then a small city of 40,000 inhabitants surrounded by a quiet wilderness. When I made a recent trip to update my earlier work, I found amazing changes. Anchorage now has 180,000 people, more than four times as many as in 1980. There’re skyscrapers, shopping centers and all the accompanying crowds and traffic jams. The forests and mountains are still nearby, but they seem diminished by the city’s great size. The discovery of oil in 1968 on the north slope of Alaska caused many of these changes. The construction of the trans-Alaska oil pipeline brought increased wealth to the state. However, there have been too many people moving to Alaska in a very short period to work on the pipeline. There is not enough housing or transportation. I think Alaska must make important decisions soon. Alaskans need to decide how to develop their natural resources and mineral wealth without destroying the wilderness and harming the wildlife.