Bài `1` :

`1.`C chemistry and physics 

`->`Dẫn chứng : She taught chemistry and physics from the lowest to the highest classes in the school. ( Câu 2 dòng 1 )

`2.`A unhappy

`->`Dẫn chứng : One year, the first class had studied chemistry for several weeks when Miss Richards suddenly asked "What is water?" There was a silence for a few seconds, and Miss Richards felt sad, but then one of the boys raised his hand. 

`3.`B not one of the most intelligent students in the class

`->`Dẫn chứng : There was a silence for a few seconds, and Miss Richards felt sad, but then one of the boys raised his hand. He was not one of the most intelligent students in the class, so she was glad that he could answer "Water is a liquid which has no color until you wash your hands in it."

`4.`D say again

`->`say again : nói lại

~ repeat : lặp lại một hành động nào đó

`5.`C She only taught the highest class

`->`Dẫn chứng : Miss Richards was a teacher at a school in England. She taught chemistry and physics from the lowest to the highest classes in the school. 

Bài `2` :

`1.`D `=>`had already 

`->`Hành động xảy ra trong 1 khoảng thời gian trong quá khứ, trước 1 mốc thời gian khác `=>`Quá khứ hoàn thành

`=>`Cấu trúc : When + S + V2/ed, S + had + Vpp

`2.`C have `=>`had

`->`Hành động xảy ra trong 1 khoảng thời gian trong quá khứ, trước 1 mốc thời gian khác `=>`Quá khứ hoàn thành

`=>`Cấu trúc : When + S + V2/ed, S + had + Vpp

Bài `3` :

`1.`examination (N)

`->`pass examination : thi đỗ