In a plaque assay, a microbiologist counts 20 plaques on a plate. how many plaque-forming units can be assumed to have been present in the original bacterium-virus mixture on the plate, if there was no dilution of the mixture prior to plating?

Read the aphorisms. be slow in choosing a friend, slower in changing. an open foe may prove a curse; but a pretended friend is worse. a true friend is the best possession. according to these aphorisms from benjamin franklin's poor richard's almanack, what might happen if a person is careless in choosing a friend? it is best not to have friends because they will usually betray you. casual friends are often the best and can be more trusted than enemies. a person who has betrayed you can sometimes become a good friend. a friend who is not carefully chosen can be worse than an enemy.

These facilities were organized and sponsored by churches or charities during the great depression in an effort to feed the homeless and needy.

When the constitutional convention laid out the framework for the executive branch they wanted