化学与生活密切相关。下列说法不正确的是( ) A.乙烯可作水果的催熟剂 B.硅胶可作袋装食品的干燥剂 C.福尔马林可作食品的保鲜剂 D.氢氧化铝可
In the good care of the nurses, the boy is recovering from his heart operation. A.quietly B.actually C.practically D.graduall
某几何体的三视图如图所示,则该几何体中,面积最大的侧面的面积为_______.
设定义在R上的函数满足,若,,则的取值范围是 A. B. C.
Don’t take the lift in a fire because the lift __________ become trapped between floors. A. must B. may C. would D. should
各可逆反应达平衡后,改变反应条件,其变化趋势正确的是
右图是下列哪种细胞处于何时期的分裂图 ①肝细胞 ②茎形成层细胞 ③蓝藻④有丝分裂前期 ⑤有丝分裂后期 ⑥有丝分裂末期A.①④ B.③⑥ C.