Lan didn’t come to the party because she had to look ______ her younger brother.
Look after = chawm sóc, trông nom ...
Look up = tra cứu ( từ điển)
Look forward to V-ing = trông đợi ....
Look at = nhìn
Đáp án là D. she had to look after her younger brother (cô phải chăm sóc em trai)