【简答题】已知AB是⊙O的直径,弦AC平分∠BAD,AD⊥CD于D,BE⊥CD于E。 求证:⑴CD是⊙O的切线; ⑵CD 2 =AD·BE。
【简答题】We often (neglect) _________ to make proper use of our bodies.
【判断题】我们必须适当地使用国家的森林资源。 We must make proper use of the forest resources of the country. ()
【单选题】We often ____ to make proper use of our bodies.
【判断题】It is proper to make use of false information to attain consumers’ interest in advertising.
【单选题】The proper use of pronouns will make an essay more _________.
【判断题】压力容器在运行过程中,如果突然发生故障,严重威胁设备和人身安全时,操作人员应立即请示领导如何处理。
【简答题】颜色模型有哪几种?试说明RGB、CMYK以及HSV颜色模型各适于在什么情况下应用?