Unit 2- Advance 1(July)

The sentence states that the museum is free, indicating that there is no requirement or obligation to pay in order to enter. Therefore, the correct modal verb to complete the sentence is "don't have to," which indicates the absence of necessity or obligation to pay.

The correct answer for the first blank is "should" because it suggests a recommendation or advice to gain experience working with animals. The correct answer for the second blank is "musn't" because it indicates that getting a spider is not allowed or should not be done.

Modal verbs, such as can, could, may, might, must, shall, should, will, would, are used to express possibility, probability, obligation, or permission. They indicate uncertainty or a lack of certainty. Therefore, they are not used to talk about things that definitely happened. Instead, other verb forms like simple past or present perfect are used to express events that have already occurred with certainty. Hence, the statement "Modal verbs are NOT used to talk about things that definitely happened" is true.

The correct answer is "MUSTN'T" because it is used to express prohibition or something that is not allowed. In this context, it is indicating that smoking inside the school is prohibited or not allowed.

The given answer lists some modal verbs of obligation, which are "have to," "should," and "must." These modal verbs are used to express different levels of obligation or necessity. "Have to" is used to indicate a strong obligation or necessity, "should" suggests a recommendation or advice, and "must" implies a strong necessity or requirement. These modal verbs are commonly used in English to convey obligations or duties in various contexts. "Could" and "may" are not modal verbs of obligation, but rather modal verbs of possibility or permission.