3. 下列属于 C. I

3.下列农作物中属于经济作物的是 () 。-|||-A.玉米 B.小麦 C.芝麻

3.下列货物中, () 必须整车运输。-|||-A.服装 B.矿石 C.

(B.)2. (C.)3. (D.)4.设函数f(x)连续，给出下列四个条件 (1)$\lim_{x\to0}\frac{|f(x)|-f(0)}{x}$存在；

3.下列材料不属于合成材料的是 ()-|||-A.电木 B.涤纶-|||-C.丁苯橡胶 D.蚕丝

3.《赛马》是由下列哪种乐器演奏的 () 。-|||-A.二胡 B.琵琶 C.古筝

3.下列属于人造纤维的是 () 。-|||-A.尼龙、锦纶 B.涤纶-|||-C.粘胶纤维 D.聚氨基甲酸酯

3.设(An)是一列集合,作 _(1)=(A)_(1), _(n)=(A)_(n)/((C)_(i)=(C)_(i)(A)_(i)) ,n=2, 3,···,证

[单选题]3． When I came into the room，he pretended ________ his homework．A． to doB． be doingC． doingD． to be doing

3.下列哪项 不是 昆虫寻花的判别依据? ()-|||-A.颜色 B.形状 C.大小 D.气味

[单选题]3． —Come and join us，Jimmy !—I-m sorry，but I-m really busy now．lf I _______ time，l would certainly go．A． will haveB． have hadC． hadD． have