A：人对地球的引力为mg
B：人对电梯的压力为m(g—a)
C：此人受的重力为m(g+a)
D：此人的视重为m(g+a)
This Sunday is grandpa's birthday. The Smith family are going to celebrate it at home, so they will have a busy weekend.
Saturday
Morning
Dad-clean the car in the garden
Mum-clean the kitchen and bedrooms of their house
Amy-have dance lessons in the gym
Rose--work on science projects in the library
Afternoon
Mum and Dad-buy some food at the supermarket
Amy and Rose-choose gifts and cards for grandpa
Evening
Watch TV together
Sunday
Mum---make a big birthday cake
Amy and Rose-wrap grandpa's gifts
Amy-help Mum cook delicious food
Rose-help Dad decorate the sitting room
Amy and Rose-give gifts to grandpa
The whole family-have a party
根据表格所提供信息，从每小题所给的A、B、C三个选项中，选出一个最佳答案。
“尽道隋亡为此河，至今千里赖通波”是颂扬隋朝大运河的句子，句中“河”的最北端就是现在的（ ）
1861年，沙皇亚历山大二世签署了废除农奴制的法令。符合该法令内容的是（ ）
