不定式作定语和状语 — 英语词汇题

根据句意，用括号中动词的适当不定式形式补全句子，并写出该不定式作定语还是状语。 1. The engineers are working day and night ______ (complete) the new space station on schedule. 2. The astronaut was the last person ______ (board) the spacecraft before the launch. 3. China has sent several probes ______ (explore) the far side of the Moon.