two species of frogs belonging to the same genus occasionally mate, but the offspring do not complete development. what is the mechanism for keeping the two frog species separate?

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

Cricket team of india australia and pakistan participant in 20-20 match . find the probability that india wins .

Healing after the death of a loved one is most difficult when: a) the bereaved is not allowed to mourn in the way he or she wishes b) the death is a long, protracted one c.) a period of grief has already elapsed d) no other mourners are present