Puzzle

 ACROSS

  1 One may say "Clean your room!"

  4 Modernist Chagall

  8 Placed in a silo, e.g.

 14 Rollover ___

 15 Berry bowl berry

 16 "Log" for raisin "ants"

 17 Earlier in time

 18 Surveillance system, briefly

 19 Have a lofty goal

 20 Quagmire

 22 Tiny bit

 24 At first

 26 Bead counters

 30 Diplomats in NYC, perhaps

 31 Reformer ___ B. Anthony

 32 Great Plains tent (var.)

 35 Lawn material

 37 Check (off)

 38 ___ O's (black-and-white cereal)

 39 You may skip one on a lake

 41 End of a scandal?

 42 Romance novelist Roberts

 43 Crystal ball, for one

 44 Meteor in an annual shower

 46 Hatred

 48 "I hear you, but it's not happening"

 50 Tearful

 51 Smoky soup legumes, or a phonetic and visual hint to interpreting two letters in 7-, 10- and 21-Down

 55 Tweaked, as crossword clues

 57 Cardiff residents

 58 ___ cake (fried fair treat)

 61 Old soda

 63 Water in the Seine

 64 Former petroleum company based in El Segundo

 65 Ocean Spray flavor prefix

 66 Lisa Ling's channel

 67 Lit parties

 68 Lemony Snicket villain Squalor

 69 Ph.D. students' jobs, often

DOWN

  1 Where some NBA teams beat the Heat

  2 Instrument with pedals

  3 Indigenous Kiwi

  4 Word after "fog" or "ice"

  5 Boston College's NCAA div.

  6 Deadly snake's warning

  7 Sit-ins and such

  8 Nonsense jazz singing

  9 Cars at charging stations

 10 Classic song, say

 11 Outdoors store

 12 Miscalculate

 13 Salon liquid

 21 Its members are often told when to applaud

 23 Boxing legend Mike

 25 Playground insistence

 27 Thai or Vietnamese

 28 Plants in a prickly garden

 29 Signed

 32 As yet

 33 Chip away at

 34 Weirdly spooky

 36 New ___, India

 40 Secret rendezvous

 45 Twist together

 47 "Sweetie"

 49 Electric guitar birches

 52 Put into office

 53 Flexible position?

 54 Avoids

 56 Serious troubles

 58 Samoyed's white coat

 59 A, to Angelina

 60 Christmas drink

 62 Hawaiian pizza meat

Solution