When a cold air mass collides with a warm air mass and lifts the warm air out of its way, there is .The rising warm air causes water vapor to condense and clouds to form. A )cold front
B ) A hot and cold front
C ) hot front
D ) None of the above

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?