`1.`C The train arrived while Elizabeth was writing a note to her friend

`→`While + was/were + Ving, S + V2/ed

`2.`D Although the water is very cold in January, we go swimming anyway.

`→`Although + S + V, S + V : Mặc dù

`3.`C Because the water was very rough, the lifeguards made all of the swimmers leave the water.

`→`Because + S + be Adj/S + V, S + V : Bởi vì

`4.`B Mike goes jogging two miles every morning before he gets ready for work.

`→`S + V, then + S + V `=`S + V + before + S + V

Tạm dịch : Mike chạy bộ hai dặm mỗi sáng trước khi anh ấy sẵn sàng đi làm.

`5.`C Going to the movies is still much cheaper than going to a concert since ticket prices might be more expensive.

`→`S1 + be + Adj_er + than + S2

`6.`Before we flew back to Ho Chi Minh City at 7pm, we went to Dong Xuan Market.

`→`Hành động xảy ra trước một hành động trong quá khứ : Before + S + V2/ed, S + V2/ed

`7.`A You need to plan your trip to America carefully so that you don’t spend all your money too quickly.

`→`Sau need + to V

- Công thức : S + V + so that + S + V