幾個(gè)關(guān)于情態(tài)動(dòng)詞選擇的問題
1.I ____ walk properly since i had that skiing accident.
答案是haven't been able to為何couldn't不可以？
2.Students ____ wear school uniforms when they have an important meeting.
答案是have to為何must不可以？
3."Why are you and Jack arguing so much these days?"
"He takes me for granted.He ____watch TV every evening and ignore me completed."
答案是wil表示“通?！?，但為何should表示“竟然”不可以？
4.I ___ pay Tracy a visit,but i'm not sure whether i will have time this Sunday.
答案是should為何must不可以？
以上，謝謝了??！