桥式起重机主梁下盖板温度大大超过上盖板温度，则上盖板变形较大，导致主梁下挠。
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生产经营单位不得将生产经营项目、场所、设备发包或者出租给没有办公场所或者相应资质的单位或者个人。
A. 正确
B. 错误
以下属于热带鱼类有（）
A. 罗非鱼
B. 鲟鱼
C. 鲫鱼
D. 多宝鱼
测含水的原油粘度时可直接测定。
A. 正确
B. 错误
A vessel not under command shall display（）.
A. two red lights at night and two black balls during daylight
B. two red lights at night and three black balls during daylight
C. three red lights at night and two black balls during daylight
D. three red lights at night and three black balls during daylight
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