46.B(yesterday⇒quá khứ đơn)
47.A(S+tobe+adj+to V)
48.C(yesterday⇒quá khứ đơn, hold là động từ bất quy tắc)
49.C(câu bị động can be+P2)
50.D(tương lai gần ,có kế hoạch trước)

I received your letter yesterday. I’m very happy to hear that everybody is all well.  Please give my regards.

Yesterday, our form teacher holded a visit to the paper mill near my school. It’s very interesting to see the process of recycling plastic things. You know, the plastic things such as old plastic bottles, cans, and plastic sandals can be reused after being recycled. The recycled plastic is used to make toys and utensils.

Next month, we are going to visit a paper mill to see how waste paper is recycled. Have you ever visited a paper mill? Write soon and share your recycling story with me.
Chúc bạn học tốtttt:>