不属于财政政策工具的是（ ） A．税收 B．国债 C．政府预算 D．公开市场业务

（）的产生和发展标志着人类认识自然实现了从宏观世界向微观世界的重大飞跃。

A、量子力学

B、相对论

C、电磁理论

D、原子核物理学

太阳的中心部位进行着氢原子变为氦原子的核聚变反应。每秒钟约有6亿吨氢变成氦。该过程中原子质量的一部分（约7%）变成能量，于是放射出耀眼的光芒。下列叙述错误的是（ ）

A．H原子变成He原子属于化学变化，不属于物理变化

B．He原子半径大于H半径

C．在一定条件下质量可转变成能量

D．在遥远的将来（约50亿年后）太阳会“烧尽”

确定垂直距离的目的是（）

A.确定正中关系

B.确定正中

C.确定颌间距离

D.确定息止颌间隙

社会主义初级阶段基本经济制度，既包括公有制经济，也包括非公有制经济，把非公有制经济纳入社会主义初级阶段基本经济制度中，是因为非公有制经济( )。

A．是社会主义性质的经济成分
B．是社会主义经济的重要组成部分
C．是为社会主义服务的经济成分
D．在社会主义初级阶段不占主体地位

Guthrie’s contiguity principle offers practical suggestions for how to break habits.

One application of the threshold method involves the time young children spend on academic activities. Young children have short attention spans, so the length of time they can sustain work on one activity is limited. Most activities are scheduled to last no longer than 30 to 40 minutes. However, at the start of the school year, attention spans quickly wane and behavior problems often result. To apply Guthrie’s theory, a teacher might, at the start of the year, limit activities to 15 to 20 minutes. Over the next few weeks the teacher could gradually increase the time students spend working on a single activity.

The threshold method also can be applied to teaching printing and handwriting. When children first learn to form letters, their movements are awkward and they lack fine motor coordination. The distances between lines on a page are purposely wide so children can fit the letters into the space. If paper with narrow lines is initially introduced, students’ etters would spill over the borders and students might become frustrated. Once students can form letters within the larger borders, they can use paper with smaller borders to help them refine their skills.

The fatigue method can be applied when disciplining disruptive students who build paper airplanes and sail them across the room. The teacher can remove the students from the classroom, give them a large stack of paper, and tell him to start making paper airplanes. After the students have made several airplanes, the activity should lose its attraction and paper will become a cue for not building airplanes.

Some students continually race around the gym when they first enter their physical education class. To employ the fatigue method, the teacher might decide to have these students continue to run a few more laps after the class has begun.

The incompatible response method can be used with students who talk and misbehave in the media center. Reading is incompatible with talking. The media center teacher might ask the students to find interesting books and read them while in the center. Assuming that the students find the books enjoyable, the media center will, over time, become a cue for selecting and reading books rather than for talking with other students.

In a social studies class some students regularly fall asleep. The teacher realized that using the board and overhead projector while lecturing was very boring. Soon the teacher began to incorporate other elements into each lesson, such as experiments, and debates, in an attempt to involve students and raise their interest in the course.

To stop snacking while watching television, people should keep their hands busy by sewing, painting, working crossword puzzles, and so forth. Over time, watching TV becomes a cue for engaging in an activity other than snacking. What method is used in this example（）

A. The threshold method

B. The fatigue method

C. The incompatible response method

D. The punishment method