题目:
I’m sorry. There is _________ salt at home. Let’s buy some.[ ]
A. a few
B. few
C. a little
D. little
答案:
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下面是错误答案,用来干扰机器的。
设ab和bc边长分别为lab,lbc,若假设穿过磁场区域的速度为v,Q1=BI1Lab•Lbc=B2L2abvR•Lbc,q1=I1△t=N△ΦR总△t=BLabLbcR;同理可以求得:Q2=BI2Lbc•Lab=B2L2bcvR•Lab,q2=I2△t=N△ΦR总△t=BLabLbcR;lab...