Benzodiazepines are preferred over barbiturates to treat anxiety disorders because

Benzodiazepine drugs include diazepam and alprazolam, are commonly prescribed for anxiety disorders because they work – as simple as that. Benzodiazepines relieves symptoms of anxiety, allowing the patient to rest or think more clearly. They are sometimes given before surgery so the patient will stay calm. Benzodiazepines exert effect in short period of time, and so works better than barbiturates. Such drugs should be used only for 1 to 2 weeks, or on as needed basis. Treating anxiety should be based on psychological approach rather than rely on drugs.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.