销毁$_SESSION['username']写法正确的是
A. $_SESSION['admin']=null
B. unset($_SESSION['admin'])
C. $_SESSION['admin']=""
D. $_SESSION['']
查看答案
What is wrong about peristalsis?
A. Its plural form is peristalses.
B. It is stimulated by the nerves in the surrounding esophageal tissue.
C. It is a series of defined cartilaginous contractions.
D. It propels the food into the stomach.
According to this TED speech, what are the four main components of the digestive system?
A. gastrointestinal tract
B. accessory organs of digestive system
C. the body’s enzymes, hormones, nerves, and blood
D. mesentery
A trio of organs that “break down food using an array of special juices” include the following organs except. （单选题）
A. pancreas
B. liver
C. duodenum
D. gallbladder
____supports and positions all digestive organs in the abdomen.
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