适用于夫妇两地分居的避孕方法是()
A.宫内节育器
B.短效口服避孕药
C.输卵管结扎术
D.探亲避孕片
E.皮下埋植
参考答案:D
Tropical cyclones are classified by form and intensity.Which system does not have closed isobars().
A.Hurricane
B.Tropical disturbance
C.Tropical depression
D.Cyclone
套利获得利润的关键是( )。
A.价格的上涨
B.价格的下跌
C.价格的变动
D.差价的变动