Present because there is not we are or -ed at the end of walk
The answer is a: trees MUST have water to grow.
Answer:
the authors purpose was to inform
The correct answer is active.
The verb in the sentence above is in the indicative mood (used for facts, as opposed to subjunctive, used for wishes and possibilities, or imperative, used for commands). This means that A and B are incorrect answers. The verb is not used in its passive form (which would be 'planned), which is why D is also incorrect.