下图为某地交通线路示意图，读图回答下列各题。
在光线较弱的环境中使用显微镜观察时，应选用（ ）
根据“用显微镜观察人的血细胞涂片”和“观察小鱼尾鳍血液的流动”的实验，回答下列问题．
Opening
Fees
Notice
Monday to Friday
10:00 a.m. – 6:00 p.m.
Adults(成人)：$ 8.00
15 – 18: $ 6.00
8 – 14: $ 3.00
Under 8: free(免费)
1. Don't feed the animals!
2. Don't litter about.
3. Don't smoke.
4. Kids under 8 can't be alone
without parents.
Saturday to Sunday
8:00 a.m. – 8:00 p.m.
____ ____ ____ ____Mrs. Hand's daughter?
我这样算
①869＋242＋758
=1111＋758
=1869
②869＋242＋758
=869＋(242＋758)
=869＋1000
我这样算
