点作直线运动,已知某瞬时加速度a=-2m/s2,t=1s时速度为铆,=2m/s,则t=2s时,该点的速度大小为()
A.0
B.-2m/s
C.4m/s
D.无法确定
参考答案:D
__________ her way through the excited crowd in the bookstore, the woman writer is surrounded by a group of admirers.
A.To make
B.Having made
C.To be made
D.Making
关于萎缩性胃炎正确的是().
A.壁细胞抗体(PCA.阳性
B.内因子抗体(IFA.阳性
C.伴有恶性贫血
D.促胃液分泌细胞阴性
E.不伴有维生素B吸收障碍