题干
A new ______ to teaching languages is being used here, and it has turned out to be very helpful to the students.
A：approach
B：mea
C：method
D：way
答案(点此获取答案解析）
A
所示是用以说明向心力和质量、半径之间关系的仪器，球p和q可以在光滑水平杆上无摩擦地滑动，两球之间用一条轻绳连接，mp＝2mq，当整个装置绕中心轴以角速度ω匀速旋转时，两球离转轴的距离保持不变，则此时( ) 