Scientific research shows that animals can show emotions like human beings. They are sometimes lively, and sometimes bad-tempered.
A．contradictory
B．instant
C．appropriate
D．flexible
塔式起重机启动前重点检查（）。
A.检查鱼尾板连接螺栓及道钉无松动
B.各安全装置和各指示仪表齐全完好
C.各齿轮箱、液压油箱的油位符合规定
D.主要部位连接螺栓无松动
E.钢丝绳磨损情况及各滑轮穿绕符合规定
