为了确保工程质量，施工单位必须建立完善的自检体系，自检体系中可不包括（）。
A.自检
B.抽检
C.交接检
D.专检
参考答案：B
She has been given three free tickets for tomorrow’s concert and she ______ there with two of her best friends.
A．has gone
B．is going
C．has been
D．went
如何正确利用尿素饲喂反刍动物？
