Based on the agreement,all payments          be made by the end of the month.

may

can

shall

will

考查情态动词。句意：根据协议，所有款项应在月底付清。shall用于法律，条款中表示必须要做的事。故选C项。

According to Professor Johnson, we don't have to read the book if we don't want to, as it is              .

worthwhile

necessary

optional

serious

考查形容词词义辨析。句意：根据约翰逊教授的说法，如果我们不想读这本书，就不必读，因为它是可选择的。A. worthwhile值得的； B. necessary 必要的；C. optional 可选择的；D. serious 严肃的，认真的。根据“  we don't have to read the book if we don't want to”可知，这本书读不读都可以，由此可知它是“可选择的”。故选C项。

Her father         a writer.

turned

grew

has turned

has become

考查系动词的区别。句意：她的父亲变成了一位作家。Turn，grow，become用作系动词均可表示“变化”，使用时要注意：become主要指一个人暂时性的身心变化或永久性的自然变化，另外还可用于指天气变化和社会的趋势；grow主要表示逐渐变化，强度变化过程；turn后接名词，往往表示意想不到的变化，名词前通常不加冠词。故选D项。

---Shall I tell Jhon about it?

---No, you            . I've told him already.

needn't

wouldn't

mustn't

shouldn't

考查情态动词。句意：---要我告诉约翰这件事情吗？--不，不必了，我已经告诉他了。A.needn't不必；B. wouldn't不会；C. musn't禁止，不允许；D. shouldn't 不应该。根据“I've told him already”，可知这里是“不必要”。故选A项。

Why don't you             ? Try to make it a win-win situation for you both.

compromise

object

salute

rate

考查动词词义辨析。句意：你为什么妥协呢？试着为你们双方创造

双赢的局面。A.compromise妥协；B.object反对；C.salute致敬；D.rate比率。由后文试着为你们双方创造双赢的局面，可知前面讲的是妥协。故选A项。

Small sailboats can easily turn over in the water ________.

if not managed carefully

if are not managed carefully

unless not managed carefully

unless are not managed carefully