周期: period, cycle...
引导: to guide, to lead (around), to conduct, to boot, introduction, primer...
赠送: to present as a gift...
迟缓: slow, sluggish...
转身: (of a person) to turn round, to face about, (of a widow) to remarry (archaic)...
口令: oral command, a word of command (used in drilling troops or gymnasts), password (used by sentry)...
记忆: to remember, to recall, memory...
银幕: movie screen...
