Điền giới từ thích hợp vào chỗ trống để hoàn thành các câu sau.
1. The store owners have been concerned ___1a___ the new mall ___1b___ a few months.
2. Nga got ___2a___late this morning because her alarm clock didn’t go ___2b___.
3. She walked ___3a___ the kitchen and put her packages ___3b___the table.
4. He made a deep impression___4a___ the members ___4b___ his English speaking club.
5. The driver in front stopped ___5a___ warning and we drove ___5b___ the back of his car