A:在氮化硅的合成反应中,N2是还原剂,SiO2是氧化剂
B:上述反应中每生成1molSi3N4,N2得到12mol电子
C:若已知上述反应为放热反应,升高温度,其平衡常数增大
D:若使压强增大,上述平衡向正反应方向移动
____ We had a lot of fun _______ (sing) in the classroom.____ She decided ________ (buy) the red dress.____ This sound made the baby ________ (cry).____ Most boys enjoy _______ (play) football after school.____ The shop is always ______ (crowd) on weekends.____ Would you like _____ (go) shopping with me?____ I saw a little girl ______ (look) for her parents on the street when I walked across it.____ ______ (be) you at the shop last Friday?____ The boy spends a lot of time ________ (practice) the piano in the room.____ Look! Who _______ (stand) near the door?
南海是我国的南大门,如图所示,某天我国一艘海监执法船在南海海域正在进行常态化巡航,在A处测得北偏东30°方向上,距离为20海里的B处有一艘不明身份的船只正在向正东方向航行,便迅速沿北偏东75°的方向前往监视巡查,经过一段时间后,在C处成功拦截不明船只,问我海监执法船在前往监视巡查的过程中行驶了多少海里(最后结果保留整数)?
(参考数据:cos75°=0.2588,sin75°=0.9659,tan75°=3.732, 3 =1.732, 2 =1.414)