Double bars , swinging boards , multi - function training machines , seesaws , jogging machines and similar facilities have formed mini - sized gymnasiums , simple but meaningful 双杠、秋千、多功能器械、跷跷板、跑步机和其他类似设备已经形成了小规模的体育馆，虽然简单，却很实用。
The see - saw will tilt toward the basketball first after the ice has melted a bit . the water won ' t be able to stay on the see - saw , so that side ' s lighter 质疑点：题目没有给出很多的具体条件，比如说跷跷板两端是否有托盘，篮球是否会滚下来？冰块融化后的水是否能留一部分在托盘上或者跷跷板上？
You will need the seesaw shrimp occur penguins would also boost a penguin missile put ice smashed then shrimp it for another one penguin meantime , until all the ice break up 你需要用跷跷板接住落下的企鹅将另外一只企鹅弹上去把坚冰打碎，然后再接住它换另外一只企鹅上去，直到将所有的冰块打碎为止。
Helicopter is hard to hover precisely for its bad stability . ordinarily , it is improved by flight control system , such like rotorcraft unmanned aerial vehicles which use bell bar or bell - hiller stabilizer bar . bell stabilizer bar , fixed across with teetering main rotor , consists of a bar and masses at two ends 贝尔稳定杆由一杆与两质量块组成,它与贝尔直升机的跷跷板旋翼垂直交叉放置,这种旋翼装置有助于加大角速度阻尼,改善贝尔直升机的稳定性,但同时也降低了操作性。
