由曲线[imgwidth="156"height="53"src="https://p.ananas.chaoxing.com/star3/origin/00e346dd386ef544f5052fb5c90e1372.png"]、[imgwidth="37"height="19"src="https://p.ananas.chaoxing.com/star3/origin/8fad2786802119320b27fc6647707e0d.png"]和[imgwidth="35"height="21"src="https://p.ananas.chaoxing.com/star3/origin/27d8820aa177e50656e6ffa3c6225a67.png"]围成的平面图形绕[imgwidth="15"height="17"src="https://p.ananas.chaoxing.com/star3/origin/b3048d8c2bbe74ff01f7d3c8915bfdef.png"]轴旋转一周所得旋转体的体积[imgwidth="28"height="19"src="https://p.ananas.chaoxing.com/star3/origin/c9d9123939953c49b1e9b6492e79f835.png"](). A: imgwidth="55"height="21"src="https://p.ananas.chaoxing.com/star3/origin/3bcbb56de7b78a2ff7eff984ee56642e.png">; B: ; C: ; D: .

下图所示机构自由度计算,( )是正确的。 A: mg src="http://p.ananas.chaoxing.com/star3/origin/cb07ca0fb12be985c301490389c1e187.jpg" B: F=3×7 –(2×9 + 2 – 2)– 2 = 1 C: F=3×7 –(2×9+ 2– 0)– 0 = 1 D: F=3×7 –(2×8+ 2 – 0)– 2 = 1 E: F=3×5 –(2×6+ 2– 0)– 0 = 1

p>已知生产某种产品的边际成本为&#91;imgwidth="137"height="24"src="https://p.ananas.chaoxing.com/star3/origin/162bf4d7fbb3bf506f39c9d034071d5a.png"&#93;,当产量由10单位减少到2单位时,总成本减少().</p A: p>; B: ; C: ; D: .

imgwidth="61"height="23"src="https://p.ananas.chaoxing.com/star3/origin/fa2250e70dd83d6407ee30b0f2f70d91.png">正极材料常用的合成方法有高温固相法和水热法等。()

下列符号表示两拍的是 A: <img src="http://p.ananas.chaoxing.com/star3/origin/fc00ca0cec8dd427dc15fc2958c82fba.jpg" /> B: <img src="http://p.ananas.chaoxing.com/star3/origin/2ab1bae8cce890765fe35f350c9da3a3.jpg" /> C: <img src="http://p.ananas.chaoxing.com/star3/origin/c161896591ea673a7e87bf05823878e9.jpg" /> D: <img src="http://p.ananas.chaoxing.com/star3/origin/f4d74c1de4a91f83bc4349e158eeeb08.jpg" />