Thêm một số ví dụ về hiện tại hoàn thành và hiện tại hoàn thành liên tiến
A : I haven’t seen your brother lately. Has he gone away ?
B : Yes, he's/he has been sent to America.
A : When did he go ?
B : He went last month.
A : Have you had any letters from him ?
B : I haven't, but his wife has...
