题目

小明在家用电吹风吹头发时发现，电吹风的电热丝不发热时，电动机仍能工作；电动机不工作时，电热丝不能发热。图5所示的电路中符合要求的是           答案： D 句型转换完成B句，使其与A句意思相同或相近。(每空一词) A：All the students are jumping up and down in order to stay warm． B：All the students are jumping up and down ________ to stay warm．