1. –Do remember to charge the battery 12 hours when you first use it.  --_________.
A. Made it      B. Got it      C. Understood it     D. Remembered it

2. This book is said to be a special one, which ___________ many events not found in other history books.
A. writes         B. covers       C. deals              D. refers

3. We arrived home at 9:00 in the evening, __________most people had already had supper.
A. at that time     B. by that time     C. at which time     D. by which time