A:will think
B:have been thinking
C:had thought
D:was thinking
下列现象中物体动能和重力势能都发生变化的是( )
如图,已知 ∠ABC=∠ABD,要使∆ABC≅∆ABD ,下列所添条件不一定成立的是( )
①26.7+147.2=
②801.6-21.9=
③20-0.85=
④15.78+2.45=
验算:
⑤33.4-9.48=
⑥13.1+120.95=
⑦100-19.2=