21. 27% of the workers from the factory seemed to have been poisoned by glue in their work. _______great percentage!
A. What a B. How C. What D. How a
22. In a TV ad£¬a happy housewife is polishing her table so shiny that her smiling reflection _______ on it.
A. has seen B. was seen C. is seen D. has been seeing
23. Driving Offence Point System is a computer-controlled system _______to reduce accident rates and make road much safer.
A. designing B. to design C. to be designed D. designed
24. Oh£¬terrible! _______I could escape£¬the flood roared into my house.
A. When B. Before C. Because D. Unless