【简答题】正弦交流电完成一次周期性变化所需要的时间,称为正弦交流电的_____;正弦交流电在1s内完成周期性变化的次数,称为正弦交流电的_____。
【判断题】New employees work in all departments.
【简答题】正弦交流电完成一次周期性变化所需要的时间,称为正弦交流电的 。
【单选题】My wedding day is a day ____________ I will never forget.
【单选题】Who are usually not introduced to new employees?
B.
The customers of the company.
【单选题】The area will become the city’s third water source, with a daily supply of over________ fresh water.
A.
7 million cubic meters’
B.
17 million cubic meters’
C.
70 million cubic meters’
D.
77 million cubic meters’
【单选题】The area will become the city’s third water source, with a daily supply of over _____ fresh water.
A.
7 million cubic meters’
B.
77 million cubic meters’
C.
17 million cubic meters’
D.
70 million cubic meters’
【单选题】黄禹锡,韩国著名生物科学家。经首尔大学调查委员会证实:在胚胎干细胞研究中,黄禹锡伪造数据图片和DNA干细胞样品;强迫下属女研究员提供卵子用于他的实验,并支付每人150万韩元。黄禹锡违背科研道德,主要体现在( )
【单选题】3颗静止通信卫星所处的位置分别在()上空