一台正向旋转的直流并励发电机接在直流电网上运行,若撤掉原动机,则发动机将()
A. 停转
B. 作为发动机反向运行
C. 作为发动机正向运行
D. 不能继续运行
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The "flesh fuel" referred to ______.
A. petrol for the car
B. au itean of gossip to remember
C. an opinion of the driver
D. something collected on the journey
对群体创伤紧急处理后,应迅速做出伤情初步评估,千万不可忽略
A. 不出声、不呻吟的伤员
B. 大声呼救的伤员
C. 颅脑损伤的伤员
D. 肢体麻痹的伤员
E. 瘫痪的伤员
一额定电压为10KV的静电电容器,其容抗值为10.5Ω,接在6KV母线上,电容器在额定电压下供给母线的无功功率为()
A. 0.719Mvar
B. 0.324Mvar
C. 7.19Mvar
D. 3.24Mvar
Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all these only if they are healthy. They mustbe well cared for to remain healthy.Your trees’ trouble may be you yourself. People spend much time and money to plant and maintain trees. Trees improve the looks of homes, parks, business, and public buildings. Yet, people who love trees the most may be the ones who cause them injury. Of course, they do not do this on purpose. They are most likely not aware of the kinds of things that injure trees. There are many people-caused tree injuries. You should become aware of them and avoid them. Learn the things that can help to keep your trees healthy.Healthy trees are beautiful. They make our world a pleasant place to live. Unhealthy trees are not as beautiful. They make our world less pleasant. Healthy trees help to cool and clean the air. They can even deaden(闷抑) sound. Unhealthy trees cannot help or protect the environment. Trees, like people, are disturbed by changes around them. Construction of building is a major cause of tree injury. According to the passage, only()trees can give us shade and products.
A. beautiful
B. old
C. healthy
D. young