瞧！我们向希望工程捐赠了很多学习用品，快来统计数字。

1. Books: seven + fourteen = _______________

2. Pens: ten + fifteen = _______________

3. Pencils: fourteen + fifteen = _______________

4. Rulers: two + eight + eighteen = _______________

5. Pencil cases: twenty + five + _______________ = twenty-nine

正常眼压为1～2kPa。