A careful decorum had to be maintained.
The principal had to be maintained "inviolate in perpetuity".
One and the same rhyme letter had to be maintained throughout the poem.
"But I made clear that pressure had to be maintained, could not stop -- and they seemed to realize that themselves".
Fields had to be cleared, fertile ground had to be maintained; there is evidence of sophisticated fertilisation from early on.
The only stipulations: public access to the beach and the boardwalk had to be maintained, and housing was off limits.
Due to the high reactivity of aluminum, high ratios of silicon to aluminum donator had to be maintained (at least 10: 10.
In order to ensure stable and reproducible droplet formation, a pressure difference ranging from −200 to −1800 Pa had to be maintained in the nozzle.
Each trial of the WM task consisted of four pairs of faces and houses, which had to be maintained during a delay of 10 s.
Kennedy made it clear that Berlin was of supreme strategic importance to the United States and that free access to the city had to be maintained.
For this particular molecule, the temperature had to be maintained at just five degrees kelvin in order for the reaction to occur in a controlled way.
