【单选题】Which of the following is NOT described in the passage?
A.
Whales migrate to breed and give birth to their young.
B.
Whale-watching in Boston in summer is attracting.
C.
Seals breed in the north before migration.
D.
Reindeer feed on grass.
【判断题】有功功率P与视在功率S之比,称为功率因数。
【单选题】It is as risky as the natural evolution of the virus that the scientists breed contagiousness into H5N1 to see if it is likely to happen.
【判断题】在电路中,有功功率与视在功率之比称为功率因数。 ( )
【判断题】视在功率与有功功率之比称为功率因数。()
【简答题】A.reign B.alter C.chock D.breed