管板与换热管的连接形式有胀接、焊接和()
A、胀接
B、焊接
C、胀焊并用
D、铆接
参考答案:C
– Your English teacher is so popular with students.
-- You are right! Jennifer’s nice to us all. She’s _____ a teacher _____ a friend for us.
A.not only; but also
B.both; and
C.either; or
D.neither; nor
只要迅速提高科学文化水平,我们才能适应大好形势的要求。