移动通信系统中,选择数字调制方式时,需要考虑哪些因素?
参考答案:
(1)误码性能要好(2)频带利用率要高(3)抗噪声,抗干扰,抗衰落(4)易于实现
W: Carol told us on the phone not to worry about her. Her left leg doesn’t hurt as much as it did yesterday.M: She’d better have it examined by a doctor anyway. And I will call her about it this evening.Q: What does the man think Carol should do().
A. See a doctor.
B. Stay in bed for a few days.
C. Get treatment in a better hospital.
D. Make a phone call to the doctor.
固定宫颈位置的主要韧带是()
A.官骶韧带
B.主韧带
C.骨盆漏斗韧带
D.阔韧带
E.圆韧带