—Where have you been these days?

—I have been to Bei Daihe with a friend      .

A．in Chinese

B．of Japan

C．of American’s

D．from Canada

有关胸外心脏按压的手法叙述错误的是（）

A.掌根置于胸壁，另掌交叉重叠

B.手指翘起，肘关节伸直

C.双肩、双臂与胸骨垂直

D.利用上身重量垂直下压

E.放松时双手方可离开胸壁