下颌运动的基本方式有__________、_________、________及________运动。
参考答案：开闭口；前伸；后退；侧向
This old custom has________ since the 18th century, and remains practically unchanged.
A. handed down
B. been handed down
C. handed out
D. been handed out
植物呼吸的最适温度，不是植物生长最好的温度.
