生物兴趣小组的同学们要调查一个池塘中青蛙近几年的个体数量变化情况。他们研究的是生命系统的[ ]
A.个体水平
B.种群水平
C.群落水平
D.生态水平
答案:B
The officer gave orders that anyone________ a gun should be reported to the police station.
A.sees take
B.see taken
C.seeing take
D.seen taking
谁是耶和华面对面所认识的?