在（ ）里填上适合的数。
（1）64=60+（ ）
（2）49=9+（ ）
（3）25+（ ）=25-（ ）
（1）4；（2）40；（3）0；0
— Has your former classmate come back from America?
— Yes, he _______ there for eight years. [ ]
A. has stayed
B. stays
C. stayed
D. had stayed
二进制数1234对应的十进制数是( )。
A．16
B．26
C．34
D．25
