It is usually warm in my hometown in March, but it ______ be rather cold sometimes.
A:must
B:can
C:should
D:would
汽车在水平地面上转弯,地面对车的摩擦力已达到最大值.当汽车的速率加大到原来的二倍时,若使车在地面转弯时仍不打滑,汽车的转弯半径应( )