A:so thick that
B:such thick that
C:thick in order that
D:thick such that
分析照片可知:
小球在做____直线运动(选填“匀速”或“变速”),其理由是:____.
①一个硫酸分子____;②2个磷原子____;③+3价的Al元素____;
④四个铵根离子____;⑤二氧化硅____;⑥氧元素含量最高的氧化物____;