在实际工作中,NPN型三极管和PNP型三极管可直接替换。
参考答案:错
I bought a pair of running shoes because I want to _____ the teachers’ relay race.
A.join
B.take part in
C.in
D.have part in
隧道爆破是交通建设的重点和关键工程,试述钻爆开挖法通常有哪几种?