一批煤炭从河北秦皇岛港运往广州市,沿途依次经过的海域是[ ]
A.渤海;黄海;南海;东海
B.渤海;黄海;东海;南海
C.南海;渤海;黄海;东海
D.东海;南海;渤海;黄海
答案:B
When asked what they would volunteer to do, ________ said they were willing to do something they could.
A.half of these
B.half of which
C.half of whom
D.half of them
妊娠期龈炎的病因是()
A.激素水平失调产生的组织炎症变化
B.由于妊娠本身引起牙龈炎症
C.女性激素的变化引起菌斑的聚集
D.女性激素的变化使牙龈对局部刺激物的敏感性增加
E.易发生在体质较弱的妇女