1.   The higher the Pclet number, the more contorted the pattern must become before this happens.

2.   Industry analysts say that oil companies, shielded from competition by government regulations, must become much leaner to remain profitable.

3.   The patients must become sick again to be useful subjects.

4.   With Pacific Rim trade expected to double in the next decade, the association says U.S. ports must become more efficient to remain competitive.