It was so cold outside yesterday evening 1_E_,like many parents waiting for their sons or daughters,with a coat under the arm 2_F_.We loving parents noticed the changes of the weather to come up with the idea-3_B_.Did they think it was a duty of the parents or were they grateful for what we did?All the lights in the teaching building were brightly on,and at 8:30 pm,the students in their school sports suits came out of the gate in twos or threes,4_A_.It was not only a competition among the students,but also among the parents-it seems to me that the parents love their only child as if they loved their pet,and that they would feel happy or unhappy if the pet,5_C_,Won a prize or fell behind.The results of their study for the students are just like the competition for the pets.Oh,poor boys and girls!Poor Dad and Mom!为什吗是AC不是CA根据句意：the students in their school sports suits came out of the gate in twos or threes,4_______（穿着校服的学生三三两两地从门口涌出来），后面肯定填表示人多的句子。所以选择A、making it a bit difficult to tell who was whom（分不清谁是谁）5_______,Won a prize or fell behind（赢得奖项或者落后），能推测出前面一定跟比赛类的有关。所以选择C、by taking a competition（通过比赛）