HAPPY EVERY DAY人教版英语必修2模拟试卷第一节:单项填空(共15小题;每小题1分,满分15分)21. His disappearance(失踪)_ by the police. A. looked at B. will be looked in C. is being looked into D. has been looked up22. Her teacher helped her so much that she bought him a beautiful pen _.A. by turns B. in return C. in answer D. in turn 23. I have no doubt _ she will come out first in the English contest. A. if B. about C. whether D. that24. The farm _once