The present invention relates to an inbred sunflower line, designated OID687R. Fuel spray F from a fuel injection nozzle is injected toward an inner peripheral wall section of the second volume in a former stage of fuel injection and toward the inclined surface of the first volume in a later stage of fuel injection, and the percentage of the fuel injection period in the former stage against the total fuel injection period is set to the range from 40% to 70%. Also disclosed is a method of preparing such copolymers. Deflective netting may be provided adjacent the accessories to prevent the ball and users from entering the space below the trampoline rebounding mat. The grenade simulating member includes an arrangement adapted to simulate a detonation of a low velocity grenade and trigger associated therewith for triggering the detonation. The operations basically include first determining a number of available processors, then allocating a recalculation engine to each available processor, distributing the formulas between the recalculation engines, and then concurrently evaluating the formulas distributed to each recalculation engine when a recalc operation is called for in the spreadsheet program.