Endotracheal aspiration should be limited to :() A: within 2 seconds B: within 5 seconds C: within 10 seconds D: within 20 seconds E: within 30 seconds

Most of the information kept in short-term memory will be stored for approximately 20 to 30 seconds, but it can be just seconds if rehearsal of the information is prevented.

确保两次启动之间的时间至少间隔 30 秒。 A: Make sure that the time between starts is a minimum of 30 seconds. B: Check that 30 seconds have elapsed between starts. C: Check that 30 seconds have timed between starts.

Theair-conditionerisrunninginthewinterandtobestopped,weshould（） A: closeFanandHumidifieratthesametime B: firstlycloseFanandthenclosehumidifierimmediately C: firstlyclosehumidifierandthencloseFanimmediately D: firstlyclosehumidifierandthencloseFanafter30seconds

It was about 30 seconds before Alex ________ from the water. we are quite scared。

17e0c472232d984.jpgIt was about 30 seconds before Alex __________from the water; we werequite scared.

30 seconds, do the test again. A: after (prep.) B: subsequent to C: delay (v.) D: elapse (v.)

An average person can remember about ______chunks within 30 seconds。 （ ）。 A: 8 B: 9 C: 7 D: 6

It was about 30 seconds before Alex ________ from the water. we are quite scared。 A: appear B: emerge C: disappear D: emend

It was about 30 seconds before Alex ______ from the water; we were quite scared. A: submerge B: emerge C: dissolve D: fade