A.换用磁性更强的磁体
B.换用电压更高的电源
C.将 N、S 极对调
D.增大线圈的匝数
答案:C
So quickly are science and technology advancing is a possibility today may be a reality tomorrow.[ ]
A. that which
B. that what
C. what
D. which
请演示心脏相对浊音界的叩诊。