1. A math test paper contains only 25 multiple-choice questions. Correct answers earn 4 points, and wrong answers deduct 1 point. A student answered all the questions and scored a total of 70 points. Then he got ( ) questions correct.
(A) 17
(B) 18
(C) 19
(D) 20
$$
-、 1 . \mathrm{C}
$$
1. Let the number of correct answers be $x$, then the number of wrong answers is $(25-x)$. According to the problem, we have
$$
4 x-(25-x)=70 .
$$