It is generally considered that no sex differences exist in the count of white corpuscles or leucocytes. The count of leucocytes in the blood of a healthy person is 4,500 to 9,500 per cu mm (cubic millimetre). When the number of white blood cells (WBC) is counted after mental or physical exertion, meals and mild activity it may increase to 10,000 and more per cu mm.
It is estimated that the erythrocytes are the most numerous cellular elements, ranging from 4,000,000 to 5,000,000 per cu mm. The red blood cell count (RBC) may change with age; when the red blood cell count is done after physical exertion and emotions it may increase.
Объяснение:
Неопределенный артикль (a/an) ставится, когда мы говорим о вещи впервые (как в первом предложении первого номера), и не ставится перед прилагательными без существительного (It is black), перед числами (he is seven), перед именами (Fred, Mary) и перед множественным числом (green apples).
Определенный артикль (the) ставится, когда мы уже говорили о предмете ранее (как во втором предложении первого номера), и может стоять перед множественным числом (the apples).
We really need to get across the river before dawn
I tried to get my point across but he won't listen
Please get down from there or you will fall!
I failed my exams and it really got me down
I wish he would stop getting me down with his rude words