下面四个等式中表示x和y成正比例关系的是（ ） A．xy=6 B．6x=y C．6x=

The committee charged with recommending a compensation package for members of a firm’s board of directors has recommended that in addition to compensation of $10000 for each board meeting attended, board members will be able to use one of the firm’s corporate jets up to twice each year and will receive a finder’s fee of 0. 1% if they identify an acquisition target that the firm acquires while the member is still on the board. Are these policies consistent with good corporate governance practices Use of Jet Finder’s fees（）①A. Yes Yes ②B. No Yes ③C. No No

A. ①

B. ②

C. ③

诊断干细胞癌时，首选的肿瘤标志物（）

A.APF

B.PSA

C.hCG

D.AFP

E.CEA

2012年6月22日“蛟龙号”载人潜水器开始7000m海试的第三次下潜，下潜深度6960m左右．“蛟龙号”的外壳用硬度大的钛合金制成．已知钛合金的密度为4.5g/cm³，钢的密度为7.9g/cm³，若将一个体积为1dm³的钢制零件用钛合金制造，其质量减轻了______g．

皮肤中的纤维性蛋白包括()

A．角蛋白

B．胶原蛋白

C．核蛋白

D．弹性蛋白

说明人工降水、消雾、消云和抑制冰雹的原理和方法。