冬季,由海陆热力差异而产生的水平气压梯度方向是()。
A.由海洋指向陆地
B.陆地指向海洋
C.平行于海岸线
D.与海岸线成10°~20°交角指向海洋
参考答案:B
You want to invite Susan to a party. Write an invitation letter to her, elaborating on the reason why such a party should be held and what activities will be arranged for them.
Do not sign your own name at the end of the letter. Use "Li Ming" instead.
Do not write the address.
根据哪些因素选择矿井通风方式?