英国工业革命期间,机器的发明和使用最早出现于( )
34+____=41
— __________. That man got his books and left a few minutes ago.
⑴5×69 (2)4×64 (3)85×9
⑷121×3 (5)47×5 (6)52×7
⑺8×44 (8)9×48 (9)209×2
积在300与400之间的算式有( )个.