单项选择题

下列叙述中属于造成目前世界粮食问题的原因是( )

A.地区的生产不平衡
B.粮食总产量的不足
C.城市人口增长太快
D.粮食单产下降
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热门 试题

单项选择题
The art of war has undergone such changes that _______.A.we no longer use any French words of the Middle AgesB.many words once common are not used any longer and they are replaced by Italian wordsC.French military terms have disappeared from the English languageD.many words once common are now only in historical use and their places have been taken by the newly-borrowed words
A.
A.we
B.many
C.French
D.many
多项选择题
关于多发性骨髓瘤的描述下列哪些是正确的()

A.这是一种骨髓内浆细胞异常增生性恶性疾病,病灶呈散在性分布
B.骨髓显像可见中央骨髓内有单个或多个显像剂局灶性分布缺损区
C.骨髓显像中常伴有外周骨髓扩张
D.骨骼显像可见多发骨质代谢增高病灶
E.骨髓显像可见多个显像剂增高病灶

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