阅读理解，判断正"T"误"F"。

       There are four people in my family: my grandma, my father, my mother and I. My fatheris a doctor.

He works hard. My mother is amaths teacher. She teaches maths very well. Her students all like her. My

grandmadoesn't work. She is old. Sometimes she helps my mother do the housework. I am aprimary

school pupil. I study hard. I think Ilive a happy life.

( ) 1. There are three people in my family.

( ) 2. My mother is a teacher.

(     ) 3. My grandma doesn't do the housework.

(     ) 4. My grandma is young.

(     ) 5. My father works in a hospital(医院). He is a doctor.

已知加氢装置反应进料32t/h，原料密度为740kg/m，反应器装填催化剂20.6t，催化剂堆比为0.78，则反应器体积空速为（）。

A、1.50

B、1.55

C、1.64

D、2.00