题目

下列各数中无理数有（ ）A. 2个 B. 3个 C. 4个 D. 5个 答案：【答案】A【解析】根据无理数是无限不循环小数，可得无理数的个数．在中，，是无理数，故选A．________ you enjoy ________ in the river?A．Are, swimmingB．Do, swimmingC．Are, to swimD．Do, to swim