题目

TV or video games can' t bring us real happiness. Instead, we should     some relaxing hobbies,such as playing sports or travelling. A.deal with                       B. take up                           C.turn down 答案：B16.下列说法正确的是（    ）A.pH=2与pH=1的硝酸中c（H+）之比为1∶10B.Na2CO3溶液中c（Na+）与c（CO）之比为2∶1C.0.2 mol·L－1与0.1 mol·L－1醋酸中c（H+）之比为2∶1D.NO2溶于水时，被氧化的n（NO2）与被还原的n（NO2）之比为3∶1