有一包固体粉末，是由CaCO3、Na2SO4、KNO3、BaCl2、CuSO4中

已知圆C经过点A（5，1），B（1，3）两点，圆心在x轴上，则C的方程是（　　）

A．（x-2）²+y²=50

B．（x+2）²+y²=10

C．（x+2）²+y²=50

D．（x-2）²+y²=10

用所给单词的适当形式完成句子。

1. The water in our city is _    __ (recycle) many times.

2. A new bridge is being      ___ (build) in the river.

3. These boys are       __ (pull) their boat out of the lake.

4. Many _         (roof) were blown away by the strong wind.

5. We can see a lot of _     _ (can) on the ground in the park.

6. The old school        _ (pull) down and a new one is being built.

7. My sister joined a university film       _ (social).

8. Some students          (dance) while others were singing.

9. You should stop          (worry) about it.

10. Our new school is the  ____.

可用藿香治疗的病证是（）。

A.湿滞中焦证

B.呕吐

C.暑湿证

D.湿温证初起

E.胎动不安

主动脉瓣狭窄在主动脉瓣区可听到粗糙的( )

A．舒张期隆隆样杂音
B．收缩期吹风样杂音
C．舒张期叹气样杂音
D．收缩期喷射性杂音
E．收缩期与舒张期拉锯样杂音

夏至在每年的几月？