请给下列算术式找答案（每题2分，共14分）。
（1）six + four = _______
A.ten                     B.seven              C.eleven
（2）three + five = _______
A.eight                   B.nine               C.twenty
（3）seven + two = _______
A.nine                    B.eight               C.forty
（4）one + five = _______
A.six                     B.thirty              C.eight
（5）three + four = _______
A.seven                   B.fifty               C.seven
（6）two + three = _______
A.five                     B.twenty-four         C.twelve
（7）four + five = _______
A.nine                     B.one hundred        C.ninety