76.（B) Why didn't Mark and Dan go sailing together?
A. Dan asked his brother to go instead.
B. Dan was in some other place.
C. Mark was in some other place.
D. Mark would like to go with John.
77.(C) Mark tried to tie the boat to the buoy so that .
A. he could spend the night on it while John was looking for help
B. he and John could go sailing again when the fog cleared
C. it wouldn't be hit by other ships
D. he might be picked up by a passing ship
78.(B） John and Mark became separated because .
A. there wasn't room for both John and Mark on the buoy
B. John couldn't control the boat and drifted away
C. Mark thought it safe to stay on the buoy but John didn't
D. John had to stay in the boat to radio for help
79.(A) What made it possible for Mark to be found on the buoy?
A. John told people where to look for him.
B. John radioed to the Good Hope to get him.
C. He shouted when he caught sight of the Good Hope.
D. The captain saw him as the fog cleared.
80.(A) The word " he " in the last sentence refers to
A. the captain that got the message
B. the captain that sent the message
C. John
D. Mark
