方位定位时，下列（）不是物标选择时应考虑的因素？
A.物标离船的远近
B.物标是否孤立、显著
C.物标的位置是否准确
D.物标附近有物危险物
参考答案：D
- How does Mrs. Green usually go to work?
- She _____ take a bus, but now she _______ riding a bike because she wants to lose weight.[ ]
A. used to; used to
B. was used to; is used to
C. used to; is used to
D. is used to; used to
在心输出量不变的情况下，舒张压升高主要是（）
A.心率加快
B.大动脉弹性增大
C.循环血量增加
D.血液黏滞性增大
E.外周阻力增大
