完成直角航线飞行有助于学生对起飞和着陆动作的学习，之一现象可称之为（）
A.水平迁移
B.正迁移
C.伴随迁移
参考答案：B
—Who is playing the piano in the classroom?
—_______ must be Susan. She plays the piano after school every day.
A．She
B．It
C．This
D．He
我国哪些权利、许可证照应当征收印花税？
