【单选题】下列化学用语或名称正确的是( )
B.
乙酸乙酯的结构简式:CH 3 CH 2 COOCH 2 CH 3
【判断题】平面体的截交线为封闭的平面图形,其形状取决于截平面所截到的棱边个数和交到平面的情况。
【判断题】低碳钢压缩实验曲线一直是上扬的,因此极限应力为无穷。
【判断题】低碳钢压缩实验曲线一直是上扬的,因此低碳钢压缩极限应力为无穷。 C. 不确定 D. 基本正确
【单选题】Only by shouting at the top of his voice _____. A. was he able to make himself hear B. he was able to make himself hear C. he was able to make himself heard D. was he able to make himself heard
【单选题】下列化学用语的表达方式正确的是( ) ①乙酸乙酯的结构简式:CH 3 CH 2 COOCH 2 CH 3 ②CO 2 分子的结构式:O=C=O ③乙烯的实验式:C 2 H 4 ④S原子的结构示意图: ⑤葡萄糖结构简式:C 6 H 12 O 6 ⑥CH 4 Si的结构式:
【判断题】低碳钢压缩实验曲线一直是上扬的,因此极限应力为无穷。