When focusing a specimen you should always start with the SCANNING objective. Scanning objective is used to put the object you want to examine in focus. After proper focusing on the object, you can now switch to power objective.
Answer:
Brain cells are very sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death.
Explanation:
Other symptoms can include: hallucinations and delusions; increased agitation and confusion; depression and other mood disorders; personality changes, such as irritability and a reduced threshold for frustration; and an inability to focus or concentrate.
Answer:Sea levels change for three main reasons: 1) As water warms and cools it expands and contracts; 2) The amount of water contained as ice on land surfaces changes over time; 3) The Earth's surface is dynamic and can move vertically.
Explanation:The first two reasons are directly caused by global temperature changes.
They do lower the activation energy but they provide an alternate pathway for the reaction to happen quicker and they do not get used up in the reaction
