When the voltage was 4.50 volts and the temperature was 23°C, what was the current when
A. 72mA
B. 81mA
C. 90mA
D. 420mA
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Which of the following findings is best explained by the competing parental interest theory？
An imprinted gene has been discovered in humans that appears to influence a child’s social skills.
B. In the imprinted genes that have been most fully studied, the female turns the gene off, while the male’s gene remains active.
C. Studies with a monogamous mouse species indicate that imprinted genes are not active.
D. One of the imprinted genes studied is known to control a growth-stimulat-ing hormone.
Supporters of the competing parental interest theory assume that:
A. only females have an interest in regulating the size of their offspring
B. only males have an interest in ensuring the health and survival of their offspring.
C. both males and females have an interest in producing as many offspring of their own sex as possible.
D. both males and females have an interest in transmitting their genetic material to as many offspring as possible.
三相异步电动机一般可直接启动的功率为()kW以下。
A. 10
B. 7
C. 16
假定你是李华，你所在的校武术队（martial arts team）正在招收学员。请给你的留学生朋友Tony写封邮件邀请他加入，内容包括：
1.具体培训安排（时间与地点）；
2.报名方式及截止日期。
注意：
1.词数100左右；
2.可适当增加细节，以使行文连贯。
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