题目

A new study says electronic toys are not helping babies learn. Even if companies are marketing them as educational, they're not teaching the babies anything at this time, said Anna Sosa the study's author. Researchers listened to audio(声音的)recordings of parents playing with their babies aged 10 months to 16 months. The researchers compared the experiences when the children played with electronic toys, traditional toys such as blocks, or when the children looked at books. What they found is that parents talked less with their babies when the babies played with electronic toys. WhX元素最高氧化物对应的水化物为H2XO4，则它对应的气态氢化物为（　　）A．HXB．H2XC．XH4D．XH3