It ( ) an od begger ( ) Mary met in he street yesterdayA was which B was whom选的是B为什么不是A 强调句

It was an od begger ( whom) Mary met in the street yesterday.这是一个强调句的结构吧,可是有人理解为是 an od begger 的定语从句, It ( ) an od begger ( ) Mary met in he street yesterdayA was which B was whom选的是B为什么不是A 强调句 OD: It is an eraser. It is an eraser? IT.an oranoe 翻译. It‘s an eraser. 英语翻译This would be neither here nor there if it were’t for the observation that having an older mother seems to be an independent risk factor for obesity.Results from the US national heart,lung and blood institute’s study found that the od It is an orange?还是Is it an orange? Birds live in it.It's an () What an interesting film it It's an interesting book It‘s fall.An owl. it's half an hour It strikes an odd note. It was an (o ) activity what color is ( )orange?It's ( ) orangeA.AN,AN B.AN,THE C.AN / D./,AN 如图,在梯形ABCD中,AD//BC,MN分别是两条对角线BD、AC的中点说明：MN//DC且MN=1/2（DA-BC）过程在下面证明：∵AD//BC∴OD/OB=OA/OC∴OD/(OB-OD)=OA/(OC-OA)∴OD/(BM+OM-OD)=OA/(CN+NO-OA)∵BM=MD=OD+OM,CN=AN=AO+OC∴OD/(OD+OM+OM