[填空题]栈的3种基本运算是：入栈、退栈和______。

"Sleep-disordered breathing" is a term for a group of conditions that can interfere with normal breathing while people sleep. These include snoring, mouth-breathing and sleep apnea. Sleep-disordered breathing can do more than just leave people feeling tired the next day. It can also affect people’s health. In children the effects can include behavioral and emotional problems.
In a new study, researchers asked parents about their children’s breathing from when they were babies up to about age six. The parents also answered questions about behavior at ages four and seven. The study involved about eleven thousand children.
Karen Bonuck at the Einstein College of Medicine in New York led the study.
Karen Bonuck: "The central finding overall is that sleep-disordered breathing is associated with a fifty percent increase in adverse neurobehavioral outcomes."
Those problems include hyperactivity, aggressiveness and problems
A. Ieaving people feeling tired.
B. Behavioral problems in children.
C. Emotional problems in children.
D. Snoring, mouth-breathing and sleep apnea.

Practically speaking, the artistic maturing of the cinema was the single-handed achievement of David W. Griffith (1875-1948). (46)Before Griffith, photography in dramatic films consisted of little more than placing the actors before a stationary camera and showing them in full length as they would have appeared on stage. From the beginning of his career as a director, however, Griffith, because of his love of Victorian painting, employed composition. He conceived of the camera image as having a foreground and a rear ground, as well as the middle distance preferred by most directors. By 1910 he was using close-ups to reveal significant details of the scene or of the acting and extreme long shots to achieve a sense of spectacle and distance. His appreciation of the camera’ s possibilities produced novel dramatic effects. (47) By splitting an event into fragments and recording each from the most suitable camera position, he could significantly vary the emphasis from