9. I used _____ fishing. a. enjoy b.to enjoy c.enjoying d.to enjoying 10. It’s hard work looking______ three children all day. a. after b.before c.about d.at 11.I can’t stand people who are cruel______ animals. a. with b.to c.on d.about 12. He died_____ a heart attack. a. with b.of c.because d.by