如图为湖边一倾角为30°的大坝的横截面示意图，水面与大坝的交点为O。一人站在A点处以速度v₀沿水平方向扔小石子，已知AO=40m，g取10m/s²。下列说法正确的是

A．若v₀=18m/s，则石块可以落入水中

B．若石块能落入水中，则v₀越大，落水时速度方向与水平面的夹角越大

C．若石块不能落入水中，则v₀越大，落到斜面上时速度方向与斜面的夹角越大

D．若石块不能落入水中，则v₀越大，落到斜面上时速度方向与斜面的夹角越小

Following a precipitous delivery, examination of the client's vagina reveals a fourth-degree laceration. Which of the following would be contraindicated when caring for this client

A．Applying cold to limit edema during the first 12 to 24 hours.

B．Instructing the client on the use of sitz-baths if ordered.

C．Instructing the client about the importance of perineal (Kegel) exercises.

D．Instructing the client to use two or more peripads to cushion the area.