45. What can we know from the above ads?
(A) If we want to go skydiving, we need to get on a planeand had better put on the parachute first.
(B) We will be able to sing well in only one month.
(C) We can’t know our plants’ thinking by using “GoogleTulip”.
(D) If we pay $2500 for the skydiving, it will take us 50minutes to experience the flights..