摘要：Scientists say it may be five or six years it is possible to test this medicine on human patients. A.since B.after C.before D.when 解析:“It be+一段时间+before- 是固定结构.该结构的意思是“要过--(长)时间才-- . 答案:C
网址：http://m.1010jiajiao.com/timu3_id_3023183[举报]
Scientists say it may be five or six years ________ it is possible to test this medicine on human patients．
- A.since
- B.after
- C.before
- D.when
Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
A. since B. after?
C. before D. when?
查看习题详情和答案>>Scientists say it may be five or six years ____ it is possible to test this medicine on human patients.
A．since B．after C．before D．when
查看习题详情和答案>>Scientists say it may be five or six years __________it is possible to test this medicine on human patients.
A.since B.after C.before D.when
查看习题详情和答案>>Scientists say it may be five or six years_______it is possible to test this medicine on human patients.
| A．when | B．after | C．before | D．since |