影响牵引阻力的因素?
参考答案:
犁体曲面形状表、曲面光滑程度,刃锋锐程度、耕深与耕宽、前进速度、土壤状况等。
He ___________all his pockets but failed to find his passport.
A.searched
B.searched for
C.in searched of
D.looked for
领队与游客发生争执后劝慰游客的首要步骤是()。
A.劝慰游客避免扩大事端
B.寻求游客对领队服务的理解
C.不辩原因先行道歉
D.忍辱负重,避免与游客公开冲突