Dot books are considered essential by many high school band instructors to the progress of drill.

There is nothing new about the primordial components of speed and surprise: they are essential to any attack, by whatever technique.

These nucleotides (6662-6687) were determined to be essential by site specific mutagenesis experiments.

It is also essential for development of nerval system by programmed cell death.

Now, they argue, conditioning may be even more essential for skiers who are lured into excessive risk-taking by their equipment.

Many concerts sell out almost immediately, so it's essential to reserve seats, by phone or ma.

A knowledge of stability is essential by this stage, and conditions must have been developed to ensure that the drug is stable in the preparation.

Still, such outings are viewed as essential by Beirut residents.

It was essential to plug a legal loophole regarding the phase of use by professionals and private individuals.

"He carried Noriega's wishes out but he was not essential by any means to the success of the venture."