IS workbook answer

Plx help me to find out the answer .Thz! :) (Understanding Integrated Science Assignments 1B) WB pg.63

1(a.)When the rubber is pressed,____________between the mirror and rubber stucker are pushed out. The air pressure outside is ________________________.

(b)The survace of the sand paper is __________,____________ are still trapped between the rubber sucker and the sand paper when the rubber sucker is pressed. Therefore______________________________________________________________.

Thz so much !