1．Not having a good________ of English can be a serious obstacle to achieving your goals．
A．demand B．appreciation
C．experience D．command
2．We feel ________ our duty to make our country a better place．(2011·天津，1)
A．it B．this C．that D．one
3．People have always been ________ about exactly how life on earth began．
A．curious B．excited
C．anxious D．careful
