The Vikings are believed ________America.
A: to have discovered
B: to discove
C: in discovering
D: to have been discovered
A: to have discovered
B: to discove
C: in discovering
D: to have been discovered
举一反三
- Madame Curie is believed ____ the radium. A: discovering B: having<br/>discovered C: to have discovered D: to discovered
- Madam Curie is believed ___ the radium. A: having discovered B: to discover C: to have discovered D: discovering
- Madame Curie is believed _________ radium (镭). A: discovering B: having discovered C: to have discovered D: to discover
- 中国大学MOOC: was believed to have discovered America.
- By the year 2010, scientists probably ______ an effective treatment for cancer. A: will have discovered B: are discovering C: will be discovering D: have discovered