Curare will bind to the receptor but it doesn't cause the ion to flow inside. This will prevent the person from sent signal to the muscle. When the person trying to move the muscle, curare will also prevent acetylcholine to bind so there will be no muscle contractions. The symptoms would be paralyzed of muscle that uses ach receptor.
The abdominopelvic is composed of the abdominal cavity and the pelvic cavity. This cavity contains the organs such as liver, stomach, spleen, gallbladder, pancreas, kidney and most of the intestines along with the internal reproductive organs and urinary tract. The navel is located in the umbilical region of the abdominopelvic cavity.
Hence, the blank can be filled with 'umbilical region'.
The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
B. Using fewer fossil fuels, such as gasoline for a car, reduces the emission of harmful pollutants into the air
