1. A dog should be checked regularly by a reterinarian to ensure that it remains in good health.
2. George has not completed the assignment yet, and Mary hasn’t either.
3. Although my sister was tired, she helped me with my homework.(Bỏ but)
4. Sinaitic is the name of an alphabet which developed its symbols from Egyptian hieroglyphics.
5. There are many different ways of comparing the economy of one nation to those of another.
1. regular -> regularly (sau động từ "checked" cần 1 trạng từ)
2. neither -> either (vì "hasn't" đã mang nghĩa phủ định)
3. bỏ "but" (vì "although" không đi với "but")
4. their -> its ("which" thay thế cho "an alphabet" là danh từ số ít)
5. those -> that (đại từ thay thế cho "the economy" là danh từ số ít)
