题目内容：

语法填空

On Thursday Mrs. Clarke locked the door and went to the women’s club as usual.

When she came home she sensed1.unusual. Had someone got in? The back door and the windows were all locked and there was2.sign of forced entry. Had anything been taken? She went from room to room checking and3.(find) her spare camera missing.

The following Thursday she went out at her usual time, but she just took a short walk in a park nearby, came home through the back door and settled down to wait and see what4.(happen).

It was 4 o’clock5.the front doorbell rang. Mrs. Clarke was making tea at the time. The bell rang again, and then she heard her letter-box6.(push) open. Picking up the kettle of boiling water, she moved quietly towards the door. A piece of7.appeared through the letter-box, and then a hand.8.wire turned and caught around the knob （圆钮）on the door-lock. Mrs. Clarke raised the kettle and poured the water9.the hand. A sharp cry was heard outside as the wire fell to the floor and the hand was10.(instant) pulled back, which was followed by the sound of running feet.