1.   Some hospitals are using twins to gather information on a variety of diseases.

2.   Ashenfelter, an economics professor at Princeton University, used twins to eliminate possible biological factors in accounting for education and income.

3.   However, when the user takes a snapshot, the camera, which uses twin lenses set at slightly different perspectives, records the exposure in a stereo image.

4.   In the past, the company had used twins to represent the gum.

5.   It is studying the aging process using twins in England and plans to study obesity and diabetes in remote parts of northeast Canada.