4.

$\text{1.}$ Films aren't usually as long as plays.

$\text{→}$ các vở kịch thường dài hơn phim ⇒ phim ko dài = các vở kịch

$\text{2.}$ The photograph isn't as big as the painting.

$\text{→}$ Bức tranh to hơn tấm ảnh ⇒ tấm ảnh ko to = bức tranh

$\text{3.}$ My painting isn't as expensive as this painting.

$\text{4.}$ This picture isn't different from the picture in our room.

$\text{→}$ Bức tranh này giống bức tranh trong phòng chúng tôi ⇒ bức tranh này ko khác bức tranh trong phòng chúng tôi.

$1.$ Film is not as long as plays.

$2.$ The photography is not as big as the painting.

$3.$ My painting is not as expensive as this painting.

$4.$ This picture is not different from the picture in our room.

`->` Cấu trúc câu so sánh bằng (với tính từ):

`S_1` + be + as + adj + as + `S_2` 

`->` Cấu trúc câu so sánh khác nhau:

`S_1` + be + (not) + different from + `S_2`