the doctor said that was a very rare __case___ of the illness（case）they have little money,so they can not __afford___ （支付得起）I _treat___ Daniel as my best friends（treat）the doctor will be __t...最后一個(gè)為什么是trained不是training用trained 是被動(dòng)語(yǔ)態(tài)，醫(yī)生接受訓(xùn)練的意思，而如果用training，就是現(xiàn)在進(jìn)行時(shí)，醫(yī)生正在訓(xùn)練，后面沒有賓語(yǔ)，而且與before 引導(dǎo)的狀語(yǔ)從句意思沖突。