A:①②
B:只有②
C:②和③
D:③和④
①57.4﹣37.5=
②7.2﹣2.8=
③4.8÷0.01=
④7.8÷0.26=
⑤42÷7.4≈(商精确到0.01)
⑥2.4×5÷2.4×5=
⑦0.1÷1+10÷0.1=