Read the following sentence carefully and select the pair of words from the given choices that appropriately fills the two blanks to render the statement grammatically correct and meaningful.

The delegates _______________ in the main hall to hear the keynote speech and _____________ the new international agreement.

The correct answer is assembled, ratify.

To determine the correct pair of words, we analyze the logical flow and grammatical context of the given sentence:
"The delegates _______________ in the main hall to hear the keynote speech and _____________ the new international agreement."

Step 1: Analyzing the first blank
The sentence describes delegates coming together in a location ("in the main hall") for a specific purpose ("to hear the keynote speech").
- assembled means gathered together in one place for a common purpose. This fits perfectly since delegates gather in a hall to listen to a speaker.
- departing (leaving) or scattered (dispersed/spread out) contradicts the context of coming together in a hall to hear a speech.
- dismissed means sent away, which is illogical prior to hearing a speech.

Step 2: Analyzing the second blank
The second verb describes the action taken by the delegates concerning "the new international agreement".
- ratify means to give formal consent to a treaty or agreement, making it officially valid. Delegates at an international convention typically ratify agreements.
- remaining is grammatically incorrect here (a present participle is used where a finite past tense verb parallel to the first blank is needed).
- cancel or draft paired with dismissed or scattered do not make coherent sense in the context of an official keynote gathering.

Hence, the option assembled, ratify appropriately fills both blanks to make the statement meaningful and grammatically correct.