How many species of sharks are ovoviviparous?

In each transformation of energy , some energy what?

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?

Gram-negative bacteria have a cell wall that is! and does not accept the stain, making itappear