以硼砂标定盐酸溶液时，硼砂的基本单元是Na2B4O7·10H2O。( )
参考答案：错
血清中检查出HBsAg和HBeAg说明此病人是（）
A.无传染性
B.有传染性
C.有免疫力
D.病情较稳定
E.恢复期
Please tell the students ________ too much noise in class. [ ]
A. to make
B. to take
C. not to take
D. not to make
