zone plate telescope
波带片望远镜，波域片望远镜

• trigon
• trigonal
• trigonal crystal system
• trigonal symmetry
• trigonal system
• trigonometric[al]
• trigonometric calculation
• trigonometric function
• trigonometric leveling
• trigonometric ray-trace method
• trigonometric ray tracing
• trigonometric survey
• trigonometry
• tri-gun colo[u]r tube
• trihedral
• trihedral corner reflector
• trihedral prism
• trim
• trimethylborate
• trimetric projection
• trimetrogon
• trimetrogon photography
• trimmer
• trimming
• trimorphism