We know that there is no life on Mars. The Viking robot missions to the Red Planet proved that. The mission was (21) ___________ to one man for the most part. Percival Lowell, a rich American businessman, suggested that Mars contained life. He was fascinated by Mars. He spent 23 years studying it. He was so (22) ___________ involved in the search for Martian life that he built his own laboratory. It housed a huge telescope. At 7,000 feet (2.13km) (23) ___________ sea level in a dry climate, it was a perfect site to view Mars. Lowell believed that he saw a network of lines (24) ___________ Mars. He also thought that the lines were built by intelligent life. There was also the chance that water was on the planet. He drew many maps in his notebooks. His idea (25) ___________ the public’s attention. People soon believed that life on Mars could exist.
A. due
B. because
C. except
D. instead
22 : (22) ____________
A. deep
B. deeply
C. depth
D. deepen
23 : (23) ___________
A. on
B. over
C. above
D. up
24 : (24) __________
A. cross
B. crossing
C. to cross
D. crossed
25 : (25) ____________
A. made
B. achieved
C. absorbed
D. drew
==== KEY
21A
22B
23C
24B
25B