they are study for tests now 这个句子没有错吗?为什么课时掌握练习册上用的是这个句子~study不用加ing吗~be动词可以和动词原形一起使用吗

They are only study（还是studying) for long time. they are study for tests now 用yesterday改为一般过去时 They are study for tasts now(用yestarday改为一般过去时) They are looking for_____ they think is suitable for study.A.thatB.at whichC.whatD.if They are not ( ) for their study.选择那个对?A.bad b.well c.good they are not good （ ）your study.A.to B.at c.for D.about They are looking for work___and still haven't got anything Are computers helpful________our study?Yes,but they are also bad_______our study and our eyes.空格内填入for 和 to英语天才们帮帮忙吧 studying in are study they the They are good for Nowadays in China some officers are unfit for their position,_____?A.are they B aren't they C.don't they D do they选什么?为什么? They never study for long.保持原句意思 They study for ______ _________ time People are always blaming their circumstances for what they are.I don’t believe in circumstances. you shouldn't study when you are Students feel sad because they didn't pass the exam,they()hard from now on A.will study all B.willall study C.all are studying D.are all studying School students have to do homework and study for t( )They don't have a lot of f( ) time in the weeYoung kids only do e( ) choresThey help w( ) up after dinnerSome jobs are good w( ) for kids to learn new things they are not the same in some ways.改同义句 they___ _they are not the same in some ways.改同义句they___ ___in some ways.I don't think differences are important in a f_____Call English Study Center at4435867 for more i______if you want to know 完形填空（只填三个）so wait for all the years round bring boriing Christmas warmer at work Why1.We can't _____ him to open the present box.2._____ are you late for class?3.the end-of-year exam is coming,_____ they must study hard for the ex