1) … none of the participants has showed any interest, numerous outdoor activities have to be cancelled
A. Whether
B. Sine
C. For
D. Which
2) We had to spend the whole month searching for better solutions, and ... customers were impressed by our efforts.
A. fortunate
B. fortunes
C. fortune
D. fortunately
3) ... proficiency in German would be of much help, it is nott a requirement for the advertised position.
A. Otherwise
B. Despite
C. Regarding
D. Although
4) The fitness club ... a steadily increasing number of customers and is eager to develop new programs.
A. see
B. seen
C. seeing
D. has seen

Anh chị giải và giải thích rõ giùm em với ạ