【正文】 hould應(yīng)該；could能夠，可表示委婉語氣或用于過去時(shí)中；would將會，將要；must必須，表示推測時(shí)，意為“一定”。根據(jù)“Must we stop the Japanese government discharging nuclear waste water into the Pacific Ocean”可知，對于日本政府向太平洋排放核廢料這個(gè)行為，我們是必須要阻止的，用must表示“必須”。20．D解析：D【詳解】句意：我們的化學(xué)老師總是告訴我們考試前怎樣用功都不為過。must一定，表示有把握的推測；may可能，表示沒有把握的推測；can可以，表示允許；would愿意，表示意愿?！獙Σ黄?，我不會再那樣做了。故選B。做情態(tài)動詞時(shí)，無人稱與數(shù)的變化，且空后用動詞原形；做實(shí)意動詞時(shí)，有人稱和數(shù)的變化，用dare to do sth。故選A。may可能；must一定；can’t不可能；musn’t禁止。10．A解析：A【詳解】句意：鍛煉是有幫助的但是它必須是有規(guī)律的鍛煉。考查情態(tài)動詞辨析。couldn’t不能，不會；wouldn’t不愿意；mustn’t禁止，不要；needn’t不需要，不必。故選B。must必須；should應(yīng)該；can可以；need需要。瑪麗借給了我們一些錢。 must C．can’t。 for D．No, we needn’t。mustn’t D．needn’t I。mustn’t5．—How do you like my new dress? —Well, if I ________ say, it is not suitable for you.A．may B．must C．have to D．should6．—Hurry up, Jack! Let’s cross the road as fast as possible.—No, you ________. Don’t you see the light is still red?A．couldn’t B．wouldn’t C．mustn’t D．needn’t7．—The high school entrance examination is ing!— Yes, our teacher tells us we ________ be too careful while taking exams.A．mustn’t B．shouldn’t C．needn’t D．can’t8．We shouldn’t throw any objects from the building. Even a small object ________ cause serious injuries or death, when dropped from a great height.A．must B．should C．may D．need9．—I don’t care what people think.—Well, you _______ . Some opinions are worth weighing.A．should B．might C．could D．would10．Exercise is helpful but it ________ be regular (規(guī)律的) exercise.A．must B．may C．can D．need11．—Who’s the man over there? Is that Mr. Black? —It ________ be him. Mr. Black is much taller than that man.A．may B．must C．can’t D．mustn’t12．— Mom, must I clean my room now?— No, you ________. You can do it after dinner.A．needn’t B．mustn’t C．shouldn’t D．can’t13．—Have you decided to take up teaching as career after graduation? —I ________ go abroad for further education instead. But it depends.A．must B．should C．may D．shall14．The boy is very brave．I ________ he ________ the tall tree．A．dare say。 for22．— What is that young lady’s job?— She ________ be a nurse, I’m not sure.A．must B．may C．need D．would23．— Listen! Tom ________ be listening to the music while doing his homework.— Let’s go upstairs to remind him to turn it off.A．should B．could C．would D．must24．—Must I finish all my homework today, Mum?—No, you ________, my dear. You can finish some tomorrow if you like.A．needn’t B．shouldn’t C．can’t D．mustn’t25．We39。 must D．may not?？疾榍閼B(tài)動詞辨析。根據(jù)“It is not only to protect yourself but also to protect others.”可知在公共場合必須戴口罩。5．C解析：C【詳解】句意：——你覺得我的新裙子怎么樣？ ——