We shouldn't be too crazy about learning English, ______ it is also too extreme to cancel English classes in schools.
下列有关生物圈的范围及其定义的叙述中,正确的是( )
为在池塘两侧的A,B两处架桥,要想测量A,B两点的距离,如图所示,找一处看得见A,B的点P,连接AP并延长到D,使PA=PD,连接BP并延长到C,使.测得CD=35m,就确定了AB也是35m,说明其中的理由;