In an electric connecting terminal, a plane portion, two pairs of piercing portions erected on both side edges at the base end side of the plane portion and a terminal connecting portion formed on the tip side of the plane portion are provided integrally. The mass of the resultant material may be very low while retaining excellent acoustic attenuation, vibration damping, and structural characteristics. The transmission mode switching part switches from a D-TxAA mode transmission to a first or second unique mode transmission in accordance with the propagation environments. A plurality of holes are formed through the body and are fluidly coupled to the interior volume. We also provide a process to make two or more viscosity grades of base oil from an olefin feed produced by thermal cracking of a waxy feed.