MSMA (monosodium methanearsonate) is an arsenic-based grass killer. It kills grassy weeds such as crabgrass and goosegrass without harming most turfgrasses. It contains organic arsenic that, according to the University of Tennessee Extension, is less harmful than aspirin.
While open-fit hearing aids are the most popular choice of hearing aids and certainly offer many benefits, they are not for everyone. The best practice before selecting a hearing aid is to have a hearing test done by a qualified hearing healthcare provider. The best style of hearing aid for an individual depends on hearing test results, dexterity, vision, communication needs, lifestyle and what they can afford.
The type of presentation aids that speakers most typically make use of are visual aids: pictures, diagrams, charts and graphs, maps, and the like. Audible aids include musical excerpts, audio speech excerpts, and sound effects. A speaker may also use fragrance samples or a food samples as olfactory or gustatory aids.