28 How are inventions of today different from those in the past?
A. They have intention of being larger.
B. They are effectively used.
C. They gradually enrich people’s lives.
D. They need less time to complete.
29 What happened to the image on the photograph of the first camera?
A. The color of image did not stay a long time.
B. The image was different after a time period.
C. The image could not remain on the paper for long.
D. The image disappeared.
30 How many years later did it take the inventors to produce the first underwater camera after the first camera?
A. 298 years
B. 389 years
C. 321 years
D. 279 years
31 The first underwater camera was ________.
A. made after one improvement
B. put in a container
C. covered with a seal
D. stuck to a box
32 How was the underwater camera in the 1980s different from the previous?
A. It could take color photos and go deeper.
B. It took color pictures without going into water.
C. It had the shape of fish.
D. It could swim like as fish.