temps (durée) (1) réflexion (1) verre (1) énergie (1) chimie (1) Chemical warfare (1) Values (1) Vacuum (1) Time (1) Spectrometer (1) Silica (1) Power resources (1) Power (Mechanics) (1) Positronium (1) Photography--Films (1) Motion pictures (1) Microfilms (1) Glass (1) Force and energy (1) Fingerprints (1) Filmstrips (1) Chemistry (1) Annihilationism (1) Yields (1) Size (1) silice (1)