1. When I reached front door, I suddenly saw strange sight last night.
A. the;不填 B. a; the C.不填a D. the; a
2. As we all know，it is impolite to read others’ letters without their permission.
A. selfish B. published C. private D. public
3. Doctors say that ________ sleep may cause the students poor memory and concentration at school .
A. lacking of B. lacked in C. lacking D. lack for
