类风湿关节炎
参考答案:
一种累及周围关节为主的多系统炎症性的自身免疫性疾病。
某人造地球卫星因受高空稀薄空气的阻力作用,绕地球运转的轨道会慢慢改变,每次测量中卫星的运动可近似地看作圆周运动,某次测量卫星的轨道半径为r1,后来变为r2且r2<r1,以Ek1和Ek2表示卫星在这两个轨道上的功能,T1和T2表示卫星在这两个轨道上绕地球运动的周期,则( )
A.Ek2<Ek1 T2<T1
B.Ek2<Ek1 T2>T1
C.Ek2>Ek1 T2<T1
D.Ek2>Ek1 T2>T1
—Why didn't you buy the gold ring?
— I ______, but I didn't have the money.[ ]
A. would have
B. bought
C. would like to
D. had bought