English! what is a common theme in h. g. dell's works "the island of dr. korean and the invisible man? "a.) danger of scientific advancement with out ethics. b.) danger of class different between upper and lower classes. c.) danger of humanity's uncontrolled exploition of nature. d.) danger of losing human relationships and means of communication.

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?