1.   Engineers are studying the most minute cracks in the World Trade Center wreckage in a quest to guarantee that no more skyscrapers will collapse.

2.   He also emphasized that the company had improved its methods since then to include an electronic probe that is better able to spot minute cracks in the tubes.

3.   The store also sells diamonds that have been drilled with lasers or whose fractures, or minute cracks, have been filled with diamond-like substances.

4.   Tires with minute cracks over large areas of the side wall are suffering from old age and should be replaced, not matter how much tread is left.