A. secretive B. weight C. centimetre D. mamba A. ha ha B. Niagara Falls C. scene D. progress A. amphibian B. world C. at the same time D. email A. last B. mixed C. terrible D. work A. period B. fast C. culture D. ambition A. precaution B. stay in touch with C. valley D. clear A. fill B. hoverboard C. drinking D. No littering A. form B. parent C. partly D. throat A. go through B. a pair of C. shyly D. depend A. sunglasses B. undulate C. Lantern Festival D. teen