Some problems you may want to try before midterm.
Exercise 2.3 (p.55) #20
Exercise 2.4 (p.66) #22
Exercise 2.6 (p.79) #10,22
Exercise 4.5 (p.201) #28
Exercise 4.6 (p.206) #5
Exercise 7.4 (p.401) #30
Exercise 7.5 (p.409) #6
Exercise 7.6 (p.423) #38