电力系统不能向负荷供应所需的足够的有功功率时,系统的频率就()。
A、要升高
B、要降低
C、会不高也不低
D、升高较轻
参考答案:B
五、单词拼写(10*1=10分)
61. He got into a p ___________when he found the house broken into.
62. If you s____________ to the morning paper it’ll be delivered to your door.
63. The students were so b___________ that some of them fell asleep.
64. The beautiful vase made in Qing Dynasty in the store is very p_________.
65. Her friend’s e___________ gave her the confidence to enter the competition.
66. During his a____________, another teacher took his place.
67. He has been living abroad since he r_________ from his job.
68. Without your a_______________, I couldn’t have succeeded.
69. We all c____________ out classmate on his becoming one of the Olympic torch holders.
70. If you g_________ something, you promise that it will definitely happen, or that you will do it for someone.
一个圆盘,无论如何倾斜旋转,而事实上所看到的可能是椭圆,甚至线段,我们都会当它是圆盘。这体现了知觉具有()
A.整体性
B.选择性
C.理解性
D.恒常性