远端型脊肌萎缩症
A.4~12mgB.5~12mgC.10~20mgD.15~40mgE.50~120mg
参考答案:B
I________all the cooking for my family,but recently I've been too busy to do it.
A.will do
B.do
C.am doing
D.had done
在墙上挂像框时,可自制一个重锤线来检查像框是否挂正,如图所示.重垂线是利用了______的原理制成的.判断像框是否挂正的标准是______.