關於物質對α粒子的阻擋本領（stopping power），下列那些正確？① ${\left[\frac{dT}{\rho dx}\right]}_r\cong 0$ ② ${\left[\frac{dT}{\rho dx}\right]}_c\cong 0$ ③ $\left[\frac{dT}{\rho dx}\right]\cong {\left[\frac{dT}{\rho dx}\right]}_c$ ④ $\left[\frac{dT}{\rho dx}\right]\cong {\left[\frac{dT}{\rho dx}\right]}_r$ ⑤ ${\left[\frac{dT}{\rho dx}\right]}_c\cong {\left[\frac{dT}{\rho dx}\right]}_r$ (r = radiative, c = collisional)