12903419 - A surveyor's level, 154711733230 - Workers checking level of a piece12073497 - Builder using a spirit level13742212 - Low water level in a river12991110 - Crash on a level crossing, illustration11709788 - A sign at 100 feet below sea level11947384 - Man switching points at a level crossing11947385 - Man switching points at a level crossing11891529 - Checking a radioactive level gauge11891532 - Wipe testing a radioactive level gauge11826747 - Silhouette of a spirit level11891797 - Measuring a sample's gamma radiation level11757567 - Woman holding a spirit level11757566 - Woman holding a spirit level13378071 - Measuring a liquid avoiding parallax error, illustration13361513 - Contour lines of a mountainous landscape, illustration13525838 - Injection of insulin into a woman's abdomen11732056 - Reading a burette of permanganate11732096 - Reading a burette of permanganate11732070 - Reading a burette of permanganate11534690 - Planting a rhododendron11591367 - Sound engineer in a control room11849810 - Medical monitoring using a mobile phone13313123 - Students writing their GCSE examination13313061 - Teenage students learning in classroom13313103 - Students smiling and jumping13313074 - Happy students playing synthesizer13313048 - Rows of desks and chairs in classroom13313094 - Teacher talking to teenage students11842597 - Nervous teenager11831779 - Chemistry experiment11831780 - Chemistry experiment12057057 - Lunar corona12057058 - Solar corona