Some students are on their exchange vacations.其中的exchange vacations是什么意思?

Some students are b_____ with the tests.We can find some trees e________ on the mountains. There are some students ___ the playground.A.in B.on C.at D.to some students are busy ( ) their homework.A,on B,with C,for D,to 找错Some students are often running on the playground every morning 翻译 The students are looking at some public signs on the Internet Some students are on their exchange vacations.其中的exchange vacations是什么意思? Some students are found totally relying on the reference books 为什么RELY加ING there're some students on the playground ,some are playing football ,some are playing basketball ( )are jumping是写the others 还是others Look Some students are singing and o____ students are dancing There are many students on the playground.Some are standing ,and __sitting.A.see B.anotherC.other Some students are very active and exercise Some students are( ) the school lidrary The students are busy__(do)some exercises Some students are taking p__near the There are many students on the playground.Some are running;_____ are playing football.A.other B.others C.the other D.another说明原因 So many students are on the playground .Some are playing soccer and（）are playing volleyballA other B another C others Some photos are on the( ) 根据短文填词.Here are some pictures of my school.There __ many students on the playground.Wome students are playing __.Some students are playing football.And other students are __ around the playground.I have a big __.Oh,there are many classmat