III.
a.
$\text{1.}$ had spent
$\text{2.}$ arrive
$\text{→}$ QKHT + before + QKD/ N/ V-ing
b.
$\text{3.}$ starts
$\text{→}$ every day chia HTD
c.
$\text{4.}$ would you do
$\text{→}$ Câu đk loại 2: $\text{If + QKD, S + would/ could/ might + V.}$
d.
$\text{5.}$ hasn't visited
$\text{→}$ HTHT + since + QKD
