People will spend more time ____ their meals.[ ]
A. eat
B. eating
C. to eat
D. ate
答案:B
“a>0”是“|a|>0”的[ ]
A.充分不必要条件
B.必要不充分条件
C.充要条件
D.既不充分也不必要条件
航向天线阵的各个天线馈入的CSB信号的相位相同。