我国进入社会主义初级阶段,社会主义制度确立的标志( )
A:新中国成立
B:三大改造完成
C:第一个五年计划完成
D:文化大革命结束
—You're right.I decide to________
Liu Maodan
Twelve years old
China
Dear Xiaohong,
You are a lovely girl. We are in the same class in the primary school. We always have a great time at school. You are my good friend. You always help me in English. Thank you very much! I will remember you forever. Good luck for the future!
Yours,
Liu Miaodan
一船在A处测得北偏东45°方向有一灯塔B,船向正东方向以每小时20海里的速度航行1.5小时到达C处时,又观测到灯塔B在北偏东15°方向上,求此时航船与灯塔相距多少海里?