没有看懂这题到底问了什么，答案解释也没看懂， 有没有大神通俗的讲解以下？
Given the following situations, determine in each case whether or not the semi-strong EMH is contradicted.

(a)        Through the introduction of a complex computer programme into the analysis of past stock price changes, a brokerage firm is able to predict price movements well enough to earn a consistent 3% profit, adjusted for risk, above normal market returns.

(b)        On the average, investors in the stock market this year are expected to earn a positive return (profit) on their investment.  Some investors will earn considerably more than others.

c) You have discovered that the square root of any given stock price multiplied by the day of the month provides an indication of the direction in price movement of that particular stock with a probability of 0.7.

d) A Securities and Exchange Commission suit was filed against Texas Gulf Sulphur Company in 1965 because its corporate employees had made unusually high profits on company stock that they had purchased after exploratory drilling had started in Ontario (in 1959) and before stock prices rose dramatically (in 1964) with the announcement of the discovery of large mineral deposits in Ontario.

以下为解释...没有看懂
(a) There does appear to be a technical inefficiency here. However, the information which enables the firm to earn consistent abnormal profits is not costless. If the computer costs are > 3% of profits then the firm is actually earning < normal returns. If the costs are < 3% then weak-form efficiency is violated and therefore so is semi-strong form efficiency.

(b) No contradiction. Positive returns are not contrary to EMH. The time value of money tells us that investors must be rewarded on average for forgoing current consumption. In addition, some investors earning more than others does not contradict EMH - investors can earn above average returns because they are lucky (they happen to be holding shares when good news comes along) or because they invest in riskier investments (securities with higher systematic risk should offer, on average, higher returns).


(c) The answer here is very similar to (a) above, except that the costs appear to be much lower. In which case it appears that weak and semi-strong form efficiency are violated.

(d) No contradiction of semi-strong form efficiency, but it does appear that strong form efficiency is violated (trading on inside information).