小儿初次感染结核杆菌至产生变态反应的时间是()
A.48~72周
B.2~3周
C.4~8周
D.10~12周
E.2~3月
参考答案:C
During storm conditions on a vessel,the mooring tensions should be adjusted so that().
A.all mooring lines have a different tension
B.the leeward lines have higher tension than the windward lines
C.the maximum tension of the most heavily loaded line does not exceed the safe working load
D.all horizontal tension forces on the windward lines are no greater than the vertical tension forces
不是常规饲料基本所谓的“老三样”的是()。
A.花生
B.豆饼
C.小麦
D.玉米