地面表面平整度是用( )工具检查。
A.经纬仪
B.托线板、线锤
C.楔形塞尺
D.直尺
E.方尺套方
参考答案:C,D
We ________ 10 English songs so far.[ ]
A. are learning
B. learnt
C. have learned
D. will learn
我国对商标权的取得采取注册取得商标权制度。()