9700÷100=____
600÷300=____
7200÷800=____
5400÷900=____
5÷14商的小数点后面第40位上的数字是几?
—I don't know if it ____ tomorrow.
—Well, if it ____, I won't go out with you.
如图①,一张四边形纸片ABCD,∠A=50°,∠C=150°.若将其按照图②所示方式折叠后,恰好MD′//AB,ND′//BC,则∠D的度数为( )