情态动词表推测与义务 — 英语填空题
题目
根据句意，用括号内情态动词的适当形式填空。According to the archive rule, every visitor ___ (must) leave a name at the front desk. The electronic log shows that the curator left the building at 5:30 and did not return; therefore, she ___ (can’t) have been in the archive at 6:00.