单选题：化学学习活动的定向环节主要是 （ ）A明确所需解决的问题B实施解决问题的方案C得出相应的结论D对问题及解决问题的过程进行反思与评价

​​​​​​​A​​​​​​​B​​​​​​​C​​​​​​​D​​​​​​​

At first the company refused to purchase the equipment, but this decision was ___ revised.AsubsequentlyBsuccessivelyCpre

材料全屏 “Museum” is a slippery word. It first meant (in Greek) anything consecrated to the Muses: a hill, a shrine, a gar

Which of the following is NOT seen as a potential danger of the Internet University?AInternet based courses may be less

The function of the sentence ---Water boils at 100 degrees Centigrade is ______.AinterrogativeBdirectiveCinformativeDper