【单选题】下列有关存储器读写速度的排列正确的是 。
【单选题】It is a very popular play, and it would be wise to ____ seats in advance.
【单选题】The cinema is usually crowded on weekends, so it would be wise to( )the seats in advance.
【单选题】It is a very popular play, and it would be wise to ________ seats in advance.
【判断题】钢液在结晶器内冷却凝固生成坯壳,进而收缩脱离结晶器壁,产生气隙。因而导热性能大大降低,使铸坯的冷却不均匀;为了减小气隙,加速坯壳生长,结晶器的下口要比上口断面略小,称结晶器倒锥度。