A:When was it
B:It was when that
C:It was whe
D:When it was that
如图是模拟膈肌运动的实验装置.请回答:
钟表上的时间为晚上8点,这时时针和分针之间的夹角(小于平角)的角的度数是( ).
47×74 =____ (8+94)÷4 =____ 38×6 =____
4−34−14 =____0.2×20%=____ 1÷13−13÷1 =____