日本是对物流标准化较重视的国家之一,标准化的速度也很快。目前日本已提出的工业标准(JIS)关于物流方面的若干草案中包括输送用包装的系列尺寸(包装模数)。( )
参考答案:对
— How long have you been here?
— Only about five minutes. Henry and Simon _____ here with me. [ ]
A. have walked
B. had walked
C. walked
D. were walking
联合固氮作用 associative nitrogen fixation