酷派电信K1的机身厚度为（）
A.8.1mm
B.7.9mm
C.8.5mm
D.9.0mm
参考答案：A
Glad to see you back. How long _____ in Russia? [ ]
A. did you stay
B. have you stayed
C. were you staying
D. have you been staying
物理学是研究自然界中______和______的一门科学．
