【简答题】决定物质性质的重要因素是物质的结构。请回答下列问题: (1)已知A和B为第三周期元素,其原子的第一至第四电离能如下表所示: 电离能/kJ·mol -1 I 1 I 2 I 3 I 4 A 578 1817 2745 11578 B 738 1451 7733 10540 A通常显 价,A的电负性 B的电负性(填“>”、“<”或“=”)。 (2)已知:波长为300 nm的紫外光的光子,光子的能量与光...
【单选题】Water is vital _______every living thing ______, without which the world would be a dead place. [ ]
【单选题】A Special Clock Every living thing has what scientists call a biological clock that controls behavior. The biological clock_____(51) plants when to form. flowers and when the flowers should open. It t...
【简答题】函数中的局部变量的值在函数调用结束后不消失而保留原则,即其占用的存储单元不释放,那么这个变量为静态局部变量。用关键字( )进行声明。
【判断题】当希望函数中的局部变量的值在函数调用后不消失,而保留原值,即其占用的存储单元不释放,这时应该指定该局部变量为“静态局部变量”,用关键字static进行声明。
【简答题】Every living thing on this planet is part of ______, for no organism lives entirely on its own.
【单选题】A Biological Clock Every living thing has whatscientists call a biological clock that controls behavior. The biological clock tells__ (51) when to form. flowers and when the flowers should open. It te...
【单选题】A Special Clock Every living thing has what scientists call a biological clock that controls behavior. The biological clock(51)plants when to form. flowers and when the flowers should open. It tells i...