1. What about walking to work? (lời gợi ý: Let's V(inf) = How/What about V_ing?)
2. It’s good for you to do physical exercise (It + tobe + adj + (for s.one) to do s.th = Doing s.th + tobe adj + (for s.one); không có V ở câu cho sẵn nhưng viết lại ta có thể thêm do (excercise)
3. He hasn't gone abroad before (This is the first time + S + V_ed/2 = S + have/has + not/never + Vp.p + before)
4. She has driven for 1 month (S + began/started + to-V/V_ing + khoảng thời gian + ago = S + have/has + Vp.p + for + khoảng thời gian)
5. I haven’t seen my uncle for two years (The last time + S + V_ed/2 + was + khoảng thời gian + ago = S + have/has + not + Vp.p + for + khoảng thời gian)