膜翅目
参考答案：
微小到大型，口器咀嚼式或嚼吸式，翅2对，膜质，前翅大，后翅小，以翅钩列连接，翅脉很特化，有的产卵器特化成螫刺，全变态或复变态.如蚂蚁
An investor does research about margin transaction and gathers the following information about the purchase of 1000 shares on the margin in which maximum amount allowed is borrowed. The purchase price is $18.50 and the initial margin requirement is 45%. The annual margin interest rate is 8.5%. The commission on purchase and sale is $35. One year later, the investor receives a dividend of $0.40 per share sells the shares for $26.50 per share. The rate of return on margin transaction is closest to:（）
A. 80.1%
B. 89.7%
C. 90.1%
"在心易了，指下难明"，意在说明：（）
A.诊脉的道理难懂
B.诊脉的方法难把握
C.脉象的变化难以把握
D.病人的情况难以得知
