下列说法正确的是（） A钛和钾都采取下面的堆积方式 B下图为金属原子在二维空间

（-2a³）²的计算结果是（　　）

A．4a⁹

B．2a⁶

C．-4a⁶

D．4a⁶

用显微镜观察英文字母“P”，在视野中看到的物像是       。使用显微镜观察时，物镜上标有10×，目镜上标有10×，那么你所观察到的物像的放大倍数是          。当光线较暗时，用反光镜的        面来对光。

声音在空气中的传播速度v与空气的密度ρ、压强p有关，下列速度的表达式（k为比例系数，无单位）中可能正确的是[ ]

A.

B.

C.

D.

投资者购买上海黄金交易所实物金条会产生哪些税收（）.

A.17%增值税

B.5%消费税

C.印花税

D.前面三项都没有

An analyst finds a stock with historical returns that are not correlated with interest rate changes. The analyst writes a report for his clients that have large allocations in fixed - income instruments and emphasizes the observed lack of correlation. The clients with allocations of fixed income instruments are the only clients to see the report. According to Standard Ⅴ (B) , Communication with Clients and Prospective Clients, the analyst has:（）

A. violated the Standard concerning fair dealings with all clients.

B. not violated the Standard.

C. violated the Standard by emphasizing the information concerning the correlation.