电子商务的任何一笔交易不包括()
A.信息流
B.商流
C.资金流
D.广告流
参考答案:D
Uncle Bill had to ______ English yesterday. [ ]
A. speaking
B. speaked
C. speak
D. speaks
支座病害中的()病害不宜采用捣垫干硬砂浆。
A、支座不平
B、支座歪斜超限
C、支座个别悬空
D、新作支承垫石厚度较薄