• It is essential ( or necessary ) that the body of the machine is [ or ( should ) be ] effectively earthed.
• It is requisite that the ос-helix of the molecules become completely straightened.
• It is essential ( or necessary ) that the body of the machine is [ or ( should ) be ] effectively earthed.
• It is requisite that the ос-helix of the molecules become completely straightened.
Циммерман М., Веденеева К.. Русско-Английский научно-технический словарь переводчика. Russian-English scientific dictionary for translators. 2012