A teletext data separation apparatus has a slice level generating circuit including a slice timing control circuit, a control register, an adder and a divider. A method for performing microwave-assisted reactions, including alkylation reactions, using ionic liquids as solvent resulted in high yields with dramatically reduced reaction times. The computer performs, on the second storage device, a second access processing responsive to an access request to the first data, upon receiving an access request to the first data after performing the first access processing. Oxidation-inhibiting regions can be formed at the first and second walls of the semiconductor region selectively with respect to the third walls.