31．Now in some schools it isn’t odd for students to go to school seven days a week．_____ would be strange．
A．To not do so B．Not to do so C．Don’t do so D．Doing not so
32．Linda was ______ the experiment a month ago, but she changed her mind at the last minute．
A．to start B．to have started
C．to be starting D．to have been started
