`14`.→He hasn't been in touch with me for three weeks
$\text{(Thì Hiện tại hoàn thành:S+Has/Have+Vpp+O)}$
`15`.→Mr.John last visited France in 1990
$\text{(S+Last+V(ed/2)+Time)}$
`16`.→It's three weeks since it rained.
$\text{(Since+Qúa Khứ Đơn)}$
`17`.→It is the first time I have eaten this kind of food.
$\text{(It is the first time+S+Has/Have+Vpp+O)}$
`18`.→She has never driven a car before
$\text{(S+Has/Have+Never+VpII+.....+Before)}$
`19`.→I last heard him was in July
$\text{(Như câu 15)}$
$\text{@TriLeCongTri}$
$\text{chúc bạn học tốt!!!!!!}$