间断性腰椎牵引的牵引重量通常为:()
A.40~60kg
B.30~40kg
C.60~70kg
D.20~30kg
E.70~80kg
参考答案:A
-- Two bottles of apple juice, please.
-- Only one bottle is left. Would you like to have ___________, sir?[ ]
A. one
B. it
C. any
D. something
智能电网是()和()发展的必然选择。
A.电网技术,自然环境
B.科学技术,社会经济
C.电网技术,社会经济
D.科学技术,自然环境