【单选题】___ six years since I began to study English.
【单选题】It _____ six years since his grandfather died. [ ]
【单选题】( )six years since I began studying English.
【多选题】白云岩的形成机理有:
A.
原生沉淀作用、准同生白云化作用、成岩白云化作用
B.
调整白云化作用、淡水白云化作用、生物白云化作用
C.
原生沉淀作用、毛细管浓缩作用、回流渗透白云化作用
【单选题】six years since I began studying English.
【判断题】我国的活性炭产量和出口量均居世界第二位。
【多选题】白云岩的形成机理有:
A.
原生沉淀作用、准同生白云化作用、成岩白云化作用
B.
调整白云化作用、淡水白云化作用、混合白云化作用
C.
原生沉淀作用、毛细管浓缩作用、回流渗透白云化作用
【单选题】six years since I began studying ENglish.
【单选题】It's six years since I _______ him. [ ]
【单选题】__________ nearly six years since I started to study English