我国平均人口密度与世界平均人口密度相比[ ]
A、已接近世界平均人口密度
B、略大于世界平均人口密度
C、是世界平均人口密度的3倍多
D、远小于世界平均人口密度
答案:C
粒子的真密度为
A.3kg/LB.2kg/LC.4kg/LD.1.5kg/LE.1kg/L
In a crossing situation,the vessel which has the other on her own starboard side shall().
A.if the circumstances of the case admit, avoid crossing ahead of the other
B.change course to port to keep out of the way
C.overtaking another
D.All of the above