A:had lost; trained
B:were losing; had trained
C:have lost; have trained
D:lost; have been training
日常生活中,下列数据接近实际的是
某物质和水反应只生成NaOH和O2,则该物质中( )
小强准备以隋唐时期的历史内容为素材,写一篇历史小论文。你认为下列切入点可供其选择的是( )
如图中的线段,直线或射线,能相交的是( )