[单选题]A． affectB． reduceC． chockD． reflect

4.极限 lim _(narrow infty )dfrac (2n+3sin n)(n)=-|||-A.∞ B.2 C.3 D.5-|||-A A-|||-B

已知 lim _(narrow infty )(a)_(n)=2 lim _(narrow infty )(b)_(n)=3已知 lim _(narrow in

[单选题]If this woolensweater is put into hot water,it tends to [shrink]．A.breakB.c

[单选题]If this woolensweater is put into hot water,it tends to [shrink]．A.breakB.c

lim _(narrow infty )dfrac ({({n)^2-n+1)}^100}({n)^200+(n)^100+1}=-|||-A O;-|||-B

数列极限lim _(narrow infty )(6(n)^2+2)sin dfrac (1)(3{n)^2+1}=( )A.B.C.2D.3数列极限

20.[单选题] 设 =cos i ,则 ()-|||-A (A) lim _(narrow infty )(m)_(n)=0-|||-~z=0;-|||-B

lim _(narrow infty )((2n+1))^2sin dfrac (1)(2{n)^2} 值是(··)。 ()A、3B、1C、2D、∞A、3B、1

[单选题]（ ） could reduce congestion in ports， significantly shortens shipping time