选择合适的介词填空。

1. It's ________ two o'clock.

2. Let's look ________ the window. A little dog  is in it.

3. Please stand ________ Jenny.

4. A snack is a little food _________ eat.

5. I'm playing ________ the baby.

6. Please smile _________ the right answer.

关于败血症的病原学检查，叙述正确的有（）

A.尽量在应用抗生素前进行血培养

B.宜反复多次送检

C.成人采血量2~3ml，婴儿1~2ml

D.有条件者应同时进行真菌和厌氧菌培养

E.严格无菌操作，避免污染