1)Birds (build) ……….. their nests in the summer and (fly) ………. to the south in the winter.
2)He (read)………………this book for an hour, but he hasn’t finished it yet.
3)After she ………......…. (explain) everything clearly, we ……..…..…. (start) our work.
4)I (work)……………for him for 10 years and he never (say)………. good morning to me.
Loga
Sinh Học lớp 12
