【单选题】He has two children,______have become world-famous scientists.
【简答题】色彩的变化是创意本身得以深化或减弱;色彩可以帮助观者识别 ,理解 ,认识其 ,并留下深刻的印象和记忆
【单选题】用双硫腙比色法测定铅时用氰化钾,溶液 pH 必须控制在()
【单选题】The writers didn't answer the letter immediately because______.
A.
he had to prepare for a test
B.
he refused to answer it
【单选题】He has two children and ____ love him.
【单选题】He has two children, have become world-famous scientiests.
【单选题】He didn’t listen to the teacher carefully. , he couldn’t answer those questions.
【单选题】He ______ think he was wrong ______ I showed the answer to him. [ ]