非谓语动词考点精编陷阱题训练221. “what do you think made mary so upset?” “_______ her new bike.”a. as she lost b. lostc. losing d. because of losing22. the research is so designed that once _______ nothing can be done to change it.a. begins b. having begunc. beginning d. begun23. though ________ money, his parents managed to send him to university. a. lacked
