当photoshop警告用户内存不够时，下列哪个解决方案是可选的：

Directions:

Thissectionistotestyourabilitytocomprehendshortpassages.Youwillheararecordedpassage.Afterthatyouwillhearfivequestions.Boththepassageandthequestionswillbereadtwotimes.Whenyouhearaquestion,youshouldcompletetheanswertoitwithawordorashortmphrase(innomorethan3words).Thequestionsandincompleteanswersareprintedinyourtestpaper.YoushouldwriteyouranswersontheAnswerSheetcorrespondingly.

16、Whatproductdoesthecompanyproduce?______.

17、Whenwasthecompanysetup?______ago.

18、Wherearetheirproductssold?Both______andabroad.

19、Accordingtothespeaker,whydotheirproductshaveagoodreputation?

Becauseofthehighqualityandgood______theyprovide.

20、Whatdoesthespeakerpromisetogiveforalargeorder?A______.

Learningtocopewithahealthproblemcancontributetoabetterlife.

天然骨料加工以()为主，人工骨料加工以（）为主。

下面哪些特性是调节层所具有的（）