在电路中,导线把电流(),构成电流的完整回路。
A.从负载引出,通过电源再送回负载
B.从电源引出,通过负载再送回电源
C.从负载引出,通过导线再送回电源
参考答案:B
同源染色体配对的过程称为(),其结果是每对染色体形成一个()。
The phenomenon that the earth is becoming warmer has attracted ______ attention.[ ]
A. a huge number of
B. a large sum of
C. a great deal of
D. a great many