it is used to make small focus adjustment, especially when using the high power objective , and permits gradual changes in thw elavation of the tube for final accurate focusing​

Which of the following represents a difference between viruses and viroids? a) viruses infect many types of cells, whereas viroids infect only prokaryotic cells. b) viruses have capsids composed of protein, whereas viroids have no capsids. c) viruses have genomes composed of rna, whereas viroids have genomes composed of dna. d) viruses cannot pass through plasmodesmata, whereas viroids can.

An 80-year-old woman comes to the urgent care clinic with dyspnoea on exertion. on physical examination, her blood pressure is 100/70, and her pulse is 75. she has no pulsus paradoxus. her jugular veins are distended, and she has distant heart sounds. in addition, she has extra third and fourth heart sounds. her liver is enlarged, and she has pedal oedema. she has occasional premature ventricular contractions on her electrocardiogram. a chest x-ray reveals clear lung fields with a dilated cardiac silhouette. her echocardiogram reveals ventricular walls with a "speckled pattern". which of the following is the most likely diagnosis? - alcoholic cardiomyopathy- amyloidosis- haemochromatosis- tuberculosis- viral myocarditis

Which method of administration would result in the highest concentration of the drug in the brain?