Tom hasn't appeared for 10 days. So I promise his parents: “I'll report back, the moment I ________ him.”
A:located
B:locate
C:was locating
D:will locate
下列现象属于凝华的是( )
空调机的遥控器是通过发射____ (选填“紫外线”、“红外线”或“可见光”)来实现对空调机的控制.空调机工作时要消耗电能,电能属于____ (选填“一次”或“二次”)能源.
如图为氢原子的能级示意图,锌的逸出功是3.34ev,那么对氢原子在能量跃迁过程中发射或吸收光子的特征认识正确的是( )