88. __________ is the situation when one hormone cannot exert its full effects without another hormone being present. Permissiveness. 89. The stimuli causing endocrine glands to secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients are called __________.
A KTM Quad 990 ATV. An all-terrain vehicle (ATV), also known as a quad, quad bike, three-wheeler, four-wheeler, or quadricycle as defined by the American National Standards Institute (ANSI) is a vehicle that travels on low-pressure tires, with a seat that is straddled by the operator, along with handlebars for steering control.
Full Definition of AIRCRAFT. : a vehicle (as an airplane or balloon) for traveling through the air. See aircraft defined for English-language learners.See aircraft defined for kids. ADVERTISEMENT.lural aircraft. : a vehicle (as an airplane or helicopter) that can travel through the air and that is supported either by its own lightness or by the action of the air against its surfaces.