【简答题】晶体中包含有N个原胞,每个原胞有n个原子,该晶体晶格振动的格波简正模式总数是多少?其中声学波和光学波各有多少?
【单选题】PID 调节器常用的传递函数形式中K p 、K i 、K d 分别表示( )
【单选题】Which of the following underlined parts is different in pronunciation from the others?
A.
Please f o cus your attention on your papers, boys and girls.
B.
She likes to show off her new cl o thes in front of her friends.
C.
I think she should impr o ve her learning methods.
D.
The boy picked a h o le in his new sweater.
【简答题】包含N个固体物理学原胞的晶体,每个布里渊区有()个k的取值,每个能带中包含()个能级,最多可以容纳 ()个电子。
【单选题】This passage is mainly about .
A.
how to make an effective business presentation
B.
how to present strong ideas in a presentation
C.
how to focus on the depth of coverage
D.
how to prepare a powerful diagram
【单选题】()年开始了世界上第一次大规模的,有组织的,纯粹以商业为目的的旅游活动。p8
【简答题】论述调节器的比例度(P)、积分时间(I)和微分时间(D)在调节过程中有何作用?
【多选题】根据安全生产事故报告和调查处理条例规定,事故调查组应履行下列职责( )。
A.
查明事故发生的经过原因,人员伤亡情况及直接经济损失
【单选题】(单项选择题) 世界上第一次大规模的、有组织的、纯粹以商业为目的的旅游活动出现于()。