5. For years, doctors ______ millions of patients’ lives with the help of microscopes.
A: have saved
B: are saving
C: will save
D: were saving
A: have saved
B: are saving
C: will save
D: were saving
举一反三
- For years, doctors ________ millions of patients’ lives with the help of microscopes. A: have saved B: are saving C: will save D: are saving
- For years, doctors ___ millions of patients’s lives with the help of microscopes. A: have saved B: are saving
- For years,doctors ___________millions of patients’ lives with . A: have saved B: ale saving C: will save D: were saving
- For years,doctors___ millions of patients’ lives with the help of microscopes. A: have saved B: are saving
- For years,doctors _________ millions of patients’ lives with the help of microscopes.