3A的直流电通过电阻R时,t时间内产生的热量为Q;现让一交流电通过电阻R,若2t

题型:选择题

问题:

3A的直流电通过电阻R时,t时间内产生的热量为Q;现让一交流电通过电阻R,若2t时间内产生的热量为Q,则该交流电流的有效值和最大值分别为(  )

A.I=3/2A,Im=3A

B.I有=3A,I=3A

C.I有= A,I A

D.I3A,Im=6A

考点:交变电流的周期和频率
题型:选择题

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

A new study of 8,000 young people in the Journal of Health and Social Behavior shows that although love can make adults live healthily and happily, it is a bad thing for young people.   小题1: The study shows that girls become more depressed than boys, and younger girls are the worst of all.

The possible reason for the connection between love and higher risk of depression for girls is "loss of self". According to the study, even though boys would say "lose themselves in a romantic relationship", this "loss of self" is much more likely to lead to depression when it happens to girls.   小题2:  They won't tell that to their parents. 

Dr. Marianm Kaufman, an expert on young people problems, says 15% to 20% young people will have depression during their growing. Trying romance often causes the depression.

She advises kids not to jump into romance too early. During growing up, it is important for young people to build strong friendships and a strong sense of self.   小题3: 

Parents should watch for signs of depression—eating or mood changes.   小题4:  . The good news is that the connection between romance and depression seems to become weak with age. Love will always make us feel young.   小题5: .

A.Young girls who have romantic relationships usually like hiding their feelings and opinions.

B.However, only maturity (成熟) gives us a chance to avoid its bad side effects.

C.Puppy love (早恋) may bring stress for young people and can lead to depression (忧郁症)

D.Parents should forbid their children’s puppy love.E. She also suggests the parents should encourage their kids to keep close to their friends, attend more interesting school activities and spend enough time with family.

F. If they see signs from their daughter or son, they need to give help.

G. Lacking love can lead young people to grow up more quickly.

题型:选择题

呕吐物和呼气有特殊蒜臭味最可能是误服了()

A.氰化物

B.硫化氢

C.阿托平

D.有机磷

E.毒蕈

题型:选择题

下列哪个不是nio包的新特点

A.内存映射技术

B.文件锁定

C.字符及编码

D.阻塞I/O

题型:选择题

多数国家认为,如果一个人具有两个以上的外国国籍,应该是()

A、取得在先的国籍的所属国法为其本国法

B、取得在后的国籍的所属国法为其本国法

C、当事人的惯常居所或住所所在国法为其本国法

D、与当事人有最密切联系的国家的法律为其本国法

题型:选择题

特种用途林中的名胜古迹和革命纪念地的林木、自然保护区的森林,只能进行抚育和更新性质的采伐。

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