A：--a
B：-a
C：-a
D：a
— Food safety has become a social focus now.
— That's why laws are made to crimes on food.
Thomas ________ Kate for two years, and they have had a child.
The plan they are considering improving greatly.
实验中，需要“加热约5mL（毫升）水至沸腾”，要用到的下列仪器是（ ）
